This is a reland of e28dadc2

The original failure was due to a stale Win32 bot. The reland failure
was due to idempotent task deduplication returning the exact same
failure. See crbug/1196064

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}

Bug: v8:11460
No-Try: true
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: Id69311cf3267ebe1297fff159de0be48b15b65a3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806546Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73795}

This reverts commit 15c78b45.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32277/overview

Original change's description:
> Reland "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
>
> This is a reland of e28dadc2
>
> Relanding to see if Win32 rel failures from
> https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
> were infra flakes. Could not repro on try bots.
>
> Original change's description:
> > [ptr-cage] Rename IsolateRoot to PtrComprCageBase
> >
> > Currently, IsolateRoot is both the address of the Isolate root and the
> > base address of the pointer compression reservation. This CL teases the
> > two uses apart by renaming IsolateRoot to PtrComprCageBase.
> >
> > - In addition to V8_COMPRESS_POINTERS, add a
> >   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
> >
> > - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> >   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> >   aliases to GetPtrComprCageBase.
> >
> > - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
> >
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> > Reviewed-by: Igor Sheludko <ishell@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
>
> No-Try: true
> Bug: v8:11460
> Tbr: ishell@chromium.org
> Tbr: rmcilroy@chromium.org
> Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169
> Reviewed-by: Shu-yu Guo <syg@chromium.org>
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73792}

Bug: v8:11460
Change-Id: Ifee92d622c43a91c15f45ef94ff739237bd2024b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806545
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73793}

This is a reland of e28dadc2

Relanding to see if Win32 rel failures from
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
were infra flakes. Could not repro on try bots.

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>

No-Try: true
Bug: v8:11460
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73792}

This reverts commit e28dadc2.

Reason for revert: failed test262 tests;; see https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/steps?succeeded=true&debug=false

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}

Bug: v8:11460
Change-Id: I19d0e28194fcdb28e89f129a7694ca3fe29fa17a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806168
Auto-Submit: Francis McCabe <fgm@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#73791}

Currently, IsolateRoot is both the address of the Isolate root and the
base address of the pointer compression reservation. This CL teases the
two uses apart by renaming IsolateRoot to PtrComprCageBase.

- In addition to V8_COMPRESS_POINTERS, add a
  V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).

- Rename GetIsolate* helpers to GetPtrComprCageBase. When
  V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
  aliases to GetPtrComprCageBase.

- Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.

Bug: v8:11460
Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73790}

Bug: v8:11525
Change-Id: I9afd7095764fdb4b15c8a3492078073624b42a11
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2763869Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73569}

This change relands the last part of https://crrev.com/c/2601880 .

ScopeInfo has a vestigial 'length' field from when it used to be a
FixedArray. This change removes that field, which saves some memory.

More specifically:

- Make ScopeInfo inherit from HeapObject, not FixedArrayBase which
  supplied the 'length' field.
- Change FactoryBase::NewScopeInfo to allocate the updated object shape.
  It maintains the existing behavior of filling the newly-allocated
  object with undefined, even though that's not a valid ScopeInfo and
  further initialization is required.
- Change a few length computations to use HeapObject::kHeaderSize rather
  than FixedArray::kHeaderSize.
- Remove an unnecessary heap verifier function.

Change-Id: I9b3980157568fdb0402fa31660949966b401fd31
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2733037Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#73278}

This is a partial reland of https://crrev.com/c/2601880 .

In preparation for ScopeInfo not being a FixedArrayBase, this change
privatizes the FixedArray-style functions that provide access to
ScopeInfo fields by index, and moves them from scope-info-inl.h to
scope-info.cc. Those functions are still used pretty heavily during
initialization (ScopeInfo::Create, etc.), but at least we can avoid
presenting them to the rest of the world.

This change also introduces a new length() function in ScopeInfo which
hides the one inherited from FixedArrayBase and computes the ScopeInfo's
length based on its flags, so that there are no remaining readers of the
'length' field.

Change-Id: I609754010723b679e5cf00f386020faaab84c17a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2718275
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73151}

This reverts commit f731e13f.

Reason for revert: perf regressions, chromium:1179757

Original change's description:
> Remove 'length' field from ScopeInfo
>
> ScopeInfo has a vestigial 'length' field from when it used to be a
> FixedArray. This change removes that field, which saves some memory.
>
> More specifically:
>
> - Make ScopeInfo inherit from HeapObject, not FixedArrayBase which
>   supplied the 'length' field.
> - Privatize the FixedArray-style functions that provide access to
>   ScopeInfo fields by index, and move them from scope-info-inl.h to
>   scope-info.cc. Those functions are still used pretty heavily during
>   initialization (ScopeInfo::Create, etc.), but at least we can avoid
>   presenting them to the rest of the world.
> - Change FactoryBase::NewScopeInfo to allocate the updated object shape.
>   It maintains the existing behavior of filling the newly-allocated
>   object with undefined, even though that's not a valid ScopeInfo and
>   further initialization is required.
> - Move part of AccessorAssembler::ScriptContextTableLookup into a new
>   Torque macro, because it used to rely on casting ScopeInfo to
>   FixedArrayBase.
> - In V8HeapExplorer::AddEntry, don't claim that ScopeInfo objects are
>   arrays. I think it makes more sense to list them under "(system)" in
>   the dev tools, like most other V8 internal types.
>
> Bug: v8:8952
> Change-Id: I8278e3a90027d4409f0d268da0fe7080754c6b8c
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2601880
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Reviewed-by: Mythri Alle <mythria@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#72830}

Bug: v8:8952
Change-Id: I00a69da79e5ac6aaae4436a41ce773ae014cc775
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2706086
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Seth Brenith <seth.brenith@microsoft.com>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72855}

ScopeInfo has a vestigial 'length' field from when it used to be a
FixedArray. This change removes that field, which saves some memory.

More specifically:

- Make ScopeInfo inherit from HeapObject, not FixedArrayBase which
  supplied the 'length' field.
- Privatize the FixedArray-style functions that provide access to
  ScopeInfo fields by index, and move them from scope-info-inl.h to
  scope-info.cc. Those functions are still used pretty heavily during
  initialization (ScopeInfo::Create, etc.), but at least we can avoid
  presenting them to the rest of the world.
- Change FactoryBase::NewScopeInfo to allocate the updated object shape.
  It maintains the existing behavior of filling the newly-allocated
  object with undefined, even though that's not a valid ScopeInfo and
  further initialization is required.
- Move part of AccessorAssembler::ScriptContextTableLookup into a new
  Torque macro, because it used to rely on casting ScopeInfo to
  FixedArrayBase.
- In V8HeapExplorer::AddEntry, don't claim that ScopeInfo objects are
  arrays. I think it makes more sense to list them under "(system)" in
  the dev tools, like most other V8 internal types.

Bug: v8:8952
Change-Id: I8278e3a90027d4409f0d268da0fe7080754c6b8c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2601880Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72830}

Torque generates runtime accessor member functions for most class fields
that are defined in .tq files, but fields with struct types are
currently omitted. This change adds those accessors. As an example, if a
.tq file defines the following:

  struct InternalClassStructElement {
    a: Smi;
    b: Smi;
  }

  class InternalClassWithStructElements extends HeapObject {
    const count: Smi;
    entries[count]: InternalClassStructElement;
  }

Then the following accessors are generated to get and set each struct
field within the 'entries' field:

  inline int entries_a(int i) const;
  inline void set_entries_a(int i, int value);

  inline int entries_b(int i) const;
  inline void set_entries_b(int i, int value);

Bug: v8:7793
Change-Id: Ia40b5918e9d09f53ad8e78bc33f8629b8d6a79fe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2676926Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72662}

Fix 1: Track Scope::needs_home_object and Scope::uses_super_property
accurately. When "eval" is seen, figure out whether it can access
"super" and if yes, set the corresponding home object as needed.

Fix 2: The object literal scope shouldn't be entered for things
inside spreads.

Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
Previous reland: https://chromium-review.googlesource.com/c/v8/v8/+/2637220

This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.

Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing

Bug: v8:9237
Bug: chromium:1167918
Bug: chromium:1167981
Bug: chromium:1167988
Bug: chromium:1168055
Bug: chromium:1171195
Bug: chromium:1171600
Change-Id: I9686e0d90cd0c1128757eca440a88748897ee91e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2655509
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72422}

This reverts commit f6450b97.

Reason for revert: ClusterFuzz bugs

Original change's description:
> Reland [super] Store home object in Context instead of JSFunction
>
> 1) Computed property keys (esp functions in them) shouldn't be inside
> the object literal scope.
>
> 2) I was using an imprecise "maybe uses super" and storing it to
> preparse data. This won't fly, since it pollutes sister scopes and
> leads to confusion wrt whether an object literal needs a home object
> or not. Made it precise (mostly cancelling changes in the original CL).
>
> 3) PreParser::NewSuperPropertyReference was creating a VariableProxy for
> this_function (which made it used) -> inconsistent scopes between
> parsing and preparsing.
>
> 4) MultipleEntryBlockContextScope was messing up the accumulator
>
> Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
>
> This saves memory (the home object doesn't need to be stored for each
> method, but only once per class) and hopefully makes the home object
> a constant in the optimized code.
>
> Detailed documentation of the changes:
> https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
>
> Bug: v8:9237, chromium:1167918, chromium:1167981, chromium:1167988, chromium:1168055
> Change-Id: I4f53f18cc18762c33e53d8c802909b42f1c33538
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637220
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72169}

TBR=marja@chromium.org,leszeks@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:9237
Bug: chromium:1167918
Bug: chromium:1167981
Bug: chromium:1167988
Bug: chromium:1168055
Bug: chromium:1171195
Bug: chromium:1171600
Change-Id: I15209f50c3fc8acf385a23f031ebb64139e2f519
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2653158Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72391}

With this change, the GC will compute the size for ScopeInfo instances
based on a combination of flags, context_local_count, and possibly
module_variable_count, rather than using the FixedArray-style length
field. After this change and a few more cleanups, we should be able to
remove that length field and save a few bytes.

Bug: v8:8952
Change-Id: Ica8e51ee106685b44fcc55556b4bb124afc91cfa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2598461
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72231}

This change adds Torque field definitions for ScopeInfo and begins to
use the Torque-generated accessors in some places. It does not change
the in-memory layout of ScopeInfo.

Torque compiler changes:

- Fix an issue where the parser created constexpr types for classes
  based on the class name rather than the `generates` clause. This meant
  that generated accessors referred to the imaginary type HashTable
  rather than the real C++ type FixedArray.
- Don't pass Isolate* through the generated runtime functions that
  implement Torque macros. Maybe we'll need it eventually, but we don't
  right now and it complicates a lot of things.
- Don't emit `kSomeFieldOffset` if some_field has an unknown offset.
  Instead, emit a member function `SomeFieldOffset()` which fetches the
  slice for some_field and returns its offset.
- Emit an `AllocatedSize()` member function for classes which have
  complex length expressions. It fetches the slice for the last field
  and performs the multiply&add to compute the total object size.
- Emit field accessors for fields with complex length expressions, using
  the new offset functions.
- Fix a few minor bugs where Torque can write uncompilable code.

With this change, most code still treats ScopeInfo like a FixedArray, so
I would like to follow up with some additional changes:

1. Generate a GC visitor for ScopeInfo and use it
2. Generate accessors for struct-typed fields (indexed or otherwise),
   and use them
3. Get rid of the FixedArray-style get and set accessors; use
   TaggedField::load and similar instead
4. Inherit from HeapObject rather than FixedArrayBase to remove the
   unnecessary `length` field

After that, there will only be one ugly part left: initialization. I
think it's possible to generate a factory function that takes a bunch of
iterator parameters and returns a fully-formed, verifiably correct
ScopeInfo instance, but doing so is more complicated than the four
mostly-mechanical changes listed above.

Bug: v8:7793
Change-Id: I55fcfe9189e4d1613c68d49e378da5dc02597b36
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2357758Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72187}

1) Computed property keys (esp functions in them) shouldn't be inside
the object literal scope.

2) I was using an imprecise "maybe uses super" and storing it to
preparse data. This won't fly, since it pollutes sister scopes and
leads to confusion wrt whether an object literal needs a home object
or not. Made it precise (mostly cancelling changes in the original CL).

3) PreParser::NewSuperPropertyReference was creating a VariableProxy for
this_function (which made it used) -> inconsistent scopes between
parsing and preparsing.

4) MultipleEntryBlockContextScope was messing up the accumulator

Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275

This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.

Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing

Bug: v8:9237, chromium:1167918, chromium:1167981, chromium:1167988, chromium:1168055
Change-Id: I4f53f18cc18762c33e53d8c802909b42f1c33538
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637220Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72169}

This reverts commit 4d5b878b.

Reason for revert: Suspected to cause a failure on ChromeOS, which is blocking the roll - https://chromium-review.googlesource.com/c/chromium/src/+/2636263

Original change's description:
> [super] Store home object in Context instead of JSFunction
>
> This saves memory (the home object doesn't need to be stored for each
> method, but only once per class) and hopefully makes the home object
> a constant in the optimized code.
>
> Detailed documentation of the changes:
> https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
>
> Bug: v8:9237
> Change-Id: Ia0925bdc8bfe54cbefcba6d10f64746d63a530c7
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72137}

TBR=marja@chromium.org,leszeks@chromium.org

Change-Id: Idc5a8240cef4da8893ccc608ee4ae0d7206a1ba8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637215Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72142}

This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.

Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing

Bug: v8:9237
Change-Id: Ia0925bdc8bfe54cbefcba6d10f64746d63a530c7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72137}

ScopeInfo objects generally start with three fields: flags, parameter
count, and local variable count. But a single read-only ScopeInfo
instance has none of those fields. This is the empty ScopeInfo, which is
used for contexts that don't correspond to any scope (the native context
and contexts for builtin functions). Since there is only ever a single
instance of the empty ScopeInfo, the memory savings of omitting these
fields is trivial, and we can simplify logic somewhat by including them.
Rather than checking for length to be zero, this change introduces a new
flag indicating that a ScopeInfo instance is the empty one.

On its own, this change doesn't provide a whole lot of value. However,
it sets us up for two further improvements, which are consistent with
the goals outlined in [1]:

1. We should fully describe ScopeInfo fields in Torque. Getting rid of
the requirement to check for emptiness would substantially simplify the
indexed field expressions.

2. ScopeInfo shouldn't inherit from FixedArray, and shouldn't begin with
a `length` field when the length can be computed from the other fields.
This would save a small amount of heap memory and avoid any possibility
of a mismatch between the two ways of computing the length.

[1] https://docs.google.com/document/d/1tiGK7_lubxPHnInI2vscUwMHfadn8gIEa1apmI8HxR4/edit#heading=h.n63k76b3zfwa

Bug: v8:8952
Change-Id: I018127698a5d91fb2a91684bc3aec2e27ee27c41
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2561598Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#71500}

This is a reland of 64caf2b0

Original change's description:
> [torque] refactor: use -tq only in filenames derived from .tq files
>
> This is to establish a naming rule for Torque-generated files:
> - If the file is called foo/bar-tq..., then it is derived from a
>   file foo/bar.tq
> - Otherwise it doesn't belong to a specific .tq file.
>
> So far, we attached -tq to all Torque-generated file names, where it
> sometimes corresponded to a .tq file name and sometimes not.
> It is not necessary to add -tq to file names to indicate that they are
> Torque-generated, since they are already in a directory called
> torque-generated, and we always refer to them as
> "torque-generated/filename", so there is no confusion even though some
> files now have the same name as a corresponding hand-written file, for
> example factory.cc.
>
> TBR: hpayer@chromium.org
> Bug: v8:7793
> Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70060}

Bug: v8:7793
TBR: hpayer@chromium.org jgruber@chromium.org
Change-Id: I6c492bc64aee1ff167e7ef401825eca9097a7f38
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2431565
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70137}

This reverts commit 64caf2b0.

Reason for revert: Seems to be causing a failure:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux/38809?

Original change's description:
> [torque] refactor: use -tq only in filenames derived from .tq files
> 
> This is to establish a naming rule for Torque-generated files:
> - If the file is called foo/bar-tq..., then it is derived from a
>   file foo/bar.tq
> - Otherwise it doesn't belong to a specific .tq file.
> 
> So far, we attached -tq to all Torque-generated file names, where it
> sometimes corresponded to a .tq file name and sometimes not.
> It is not necessary to add -tq to file names to indicate that they are
> Torque-generated, since they are already in a directory called
> torque-generated, and we always refer to them as
> "torque-generated/filename", so there is no confusion even though some
> files now have the same name as a corresponding hand-written file, for
> example factory.cc.
> 
> TBR: hpayer@chromium.org
> Bug: v8:7793
> Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70060}

TBR=jgruber@chromium.org,tebbi@chromium.org

Change-Id: I6960fe540861947536c6ddfc0f4887ea80899fae
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2424486Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Francis McCabe <fgm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70065}

This is to establish a naming rule for Torque-generated files:
- If the file is called foo/bar-tq..., then it is derived from a
  file foo/bar.tq
- Otherwise it doesn't belong to a specific .tq file.

So far, we attached -tq to all Torque-generated file names, where it
sometimes corresponded to a .tq file name and sometimes not.
It is not necessary to add -tq to file names to indicate that they are
Torque-generated, since they are already in a directory called
torque-generated, and we always refer to them as
"torque-generated/filename", so there is no confusion even though some
files now have the same name as a corresponding hand-written file, for
example factory.cc.

TBR: hpayer@chromium.org
Bug: v8:7793
Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70060}

This changes black/white list to block/allow list.

Bug: v8:10619
Change-Id: Id55d72f90891670ca57b62dfeb6b3251025927dc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2257228Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68464}

Remove OffThreadHandle, HandleOrOffThreadHandle, and HandleFor, and
make the OffThreadIsolate allocate "real" Handles. Rather than using
the main-thread Isolate's handle scopes, these off-thread Handles are
backed by a Zone, which is tied to the lifetime of the nearest
OffThreadHandleScope. Eventually, we'll likely want to merge the
implementation of OffThreadHandleScope and HandleScope, but currently
the latter is too tightly coupled to the main thread to do so.

Bug: chromium:1011762
Change-Id: I2a6361931fe3f90a7bef4cc28ee42155fa8d062f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2071865Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66516}

The list of forward declarations required in the generated file
bit-fields-tq.h is already somewhat unwieldy and will run into serious
problems when we attempt to use enums that are defined within classes,
such as JSDateTimeFormat::DateTimeStyle. After a brief discussion today,
the cleanest solution we arrived at is to generate macros instead.

Change-Id: I654e10efbab5a1a0a340fa565c51ff1da34badaa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2050830Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#66240}

Make Scope allocation and ScopeInfo creation Isolate-templated. This
includes making SourceTextModuleInfo allocation templated -- modules
aren't currently streamed off-thread, but will hopefully be in the
future, so this future-proofs them against that.

Bug: chromium:1011762
Change-Id: I8954e08e8e81489eb821b5f62ec35a5be31fce09
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2043790Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66197}

Changing script context handling from bytecode based to metadata on the
function. This fixes the debugger to explicitly check the code rather
than implicitly relying on a NewScriptContext bytecode causing side
effects.

Bug: chromium:1043151
Tbr: ulan@chromium.org
Change-Id: I38c5c04d7c76155e0a055ae6efd57f25986bdb7d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2013117Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65920}

Reason: Breaks side-effect free debug evaluate for let/const declarations

Revert "[interpreter/runtime] Create ScriptContext before Script invocation"

This reverts commit 9e51f79e.

Revert "[interpreter/runtime] Hole script let/const requiring initialization in NewScriptContext"

This reverts commit a128e38f.

TBR=verwaest@chromium.org,leszeks@chromium.org,szuend@chromium.org,ulan@chromium.org

Bug: chromium:1043151
Change-Id: Ib802789f45f8d7dbb4c2ccc30c6246e32155a92b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2013112
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65915}

This way we don't need to generate bytecodes to push the context.

This drops the stack trace for redeclaration SyntaxErrors but keeps the
message location. This is in line with what we do for other
SyntaxErrors.

Change-Id: Id8e3cc348b4d56a8196753baf51cfd810f07512b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1997439
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65810}

In the process:

* Rework the Torque definition of ScopeInfo to enable direct
  field-style access of ScopeFlags, removing some dead code in
  the process.
* Allow implicit FromConstexpr conversion from subtypes of
  'constexpr A' to other types. This makes it possible/easy to
  convert constexpr versions of enums to other types, since the
  constexpr version of the enum isn't addressable. It's namespace
  isn't a valid namespace and is an implementation detail anyway.
* Cleanup LanguageMode: Language mode is now an enum and directly
  mirrors the C++-side definition rather than being a Smi. With
  the changes above, a new type LanguageModeSmi is introduced
  that is the Smi representation of LanguageMode that can be
  implicitly casted from constexpr LanguageMode values.

Change-Id: I190412f95e02905f445d149883fbf1f2b8ed757b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1977159
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65561}

This CL is a prepatory step towards moving the stack locals blacklist
from the DebugEvaluateContext to the respective {ScopeInfo} objects.

The locals blacklist is used during local debug evaluate to
decide whether a context lookup can advance the context chain
upwards, or if lookup needs to stop at the current scope.

This CL also introduces a "Recreate" static helper method, that
allows an existing ScopeInfo to be cloned, but with a locals
blacklist attached. This will be needed since blacklists are only
created on-demand during debugging.

R=leszeks@chromium.org

Bug: chromium:1027475, v8:9938
Change-Id: I673dbc99ce9fdc84cb5cda3f9710ba2b76ab92ee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1946349
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65380}

utils.h itself is fairly large and contains lots of unrelated functions
as well as having a fair number of dependencies itself, so this splits
bounds checking and bit field operations into their own headers in base
and replaces uses of utils.h with the more appropriate header where
possible. (Also fixes some cases where other headers were previously
brought in transitively).

Bug: v8:9810, v8:8912
Change-Id: I76c53f953848a57e2c5bfad6ce45abcd6d2a4f1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1916604Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64983}

Design doc: bit.ly/v8-repl-mode

This CL adds a new REPL mode that can be used via
DebugEvaluate::GlobalREPL. REPL mode only implements re-declaration
of 'let' bindings at the moment. Example:

REPL Input 1: let x = 21;
REPL Input 2: let x = 42;

This would normally throw a SyntaxError, but works in REPL mode.

The implementation is done by:
  - Setting a 'repl mode' bit on {Script}, {ScopeInfo}, {ParseInfo}
    and script {Scope}.
  - Each global let declaration still gets a slot reserved in the
    respective {ScriptContext}.
  - When a new REPL mode {ScriptContext} is created, name clashes
    for let bindings are not reported as errors.
  - Declarations, loads and stores for global let in REPL mode are
    now "load/store global" instead of accessing their respective
    context slot directly. This causes a lookup in the ScriptContextTable
    where the found slot for each name is guaranteed to be the same
    (the first one).

Bug: chromium:1004193, chromium:1018158
Change-Id: Ia6ab526b9f696400dbb8bfb611a4d43606119a47
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1876061
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64793}

This reverts commit 10883f56.

Reason for revert: Causes bytecode mismatch

Bug:chromium:1020538, chromium:1021457

Original change's description:
> [hole-check-elimination] Simplest possible hole check elimination
>
> doc: https://docs.google.com/document/d/1Y9uF3hS2aUrwKU56vGxlvEs_IiGgmWSzau8097Y-XBM/edit
>
> Bug: v8:7427
> Change-Id: Iedd36c146cefff7e6687fdad48d263889c5c8347
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1778902
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63913}

TBR=rmcilroy@chromium.org,leszeks@chromium.org,verwaest@chromium.org,joshualitt@chromium.org

Bug: v8:7427
Change-Id: Ib4369a3560e929692585c4546435684deae5ee9b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1899163
Commit-Queue: Joshua Litt <joshualitt@chromium.org>
Reviewed-by: Joshua Litt <joshualitt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64789}

A bit was added in the context length slot to indicate if
the context had an extension slot. It turns out that
we need this information much earlier and so this flag is now
in the scope info instead.

This CL removes this bit from length, since it was not
used anymore.

I also renamed HasContextExtension to HasContextExtensionSlot
to differentiate from Context::has_extension which returns
true only if the context has an extension slot and the
extension is not the undefined object.

Bug: v8:9744
Change-Id: I7c37105b7afed34e8f480a64596fab285388f21b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1879935
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64577}

The native context used an empty function scope info. This is inconsistent with the fact the native context has an extension slot, since the empty function scope info doesn't have the extension slot flag set.

This CL creates a scope info dedicated for the native context with the flag set.

Bug: v8:9744
Change-Id: I00459e9a0ca75dd7a0e2add5e9e61747d0635f39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1876821
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64550}

Original change's description:
> [runtime] Remove extension slots from context objects
>
> Context objects have an extension slot, which contains further
> additional data that depends on the type of the context.
>
> This CL removes the extension slot from contexts that don't need
> them, hence reducing memory.
>
> The following contexts will still have an extension slot: native,
> module, await, block and with contexts. See objects/contexts.h for
> what the slot is used for.
> The following contexts will not have an extension slot anymore (they
> were not used before): script, catch and builtin contexts.
> Eval and function contexts only have the extension slot if they
> contain a sloppy eval.
>
> Bug: v8:9744
> Change-Id: I8ca56c22fa02437bbac392ea72174ebfca80e030
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863191
> Commit-Queue: Victor Gomes <victorgomes@google.com>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Auto-Submit: Victor Gomes <victorgomes@google.com>
> Cr-Commit-Position: refs/heads/master@{#64372}

TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org

Bug: v8:9744
Change-Id: I8700ed2fa62c89e86c39bb16ac3167f38ea8d63f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1873695
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64477}

This reverts commit 392a1217.

Reason for revert: Several failures on mac64 gc stress: https://ci.chromium.org/p/v8/builders/ci/V8%20Mac64%20GC%20Stress/9747

Original change's description:
> Reland "Reland "[runtime] Remove extension slots from context objects""
> 
> This is a reland of c48096d4
> 
> Original change's description:
> > Reland "[runtime] Remove extension slots from context objects"
> >
> > This is a reland of c07c02e1
> >
> > Original change's description:
> > > [runtime] Remove extension slots from context objects
> > >
> > > Context objects have an extension slot, which contains further
> > > additional data that depends on the type of the context.
> > >
> > > This CL removes the extension slot from contexts that don't need
> > > them, hence reducing memory.
> > >
> > > The following contexts will still have an extension slot: native,
> > > module, await, block and with contexts. See objects/contexts.h for
> > > what the slot is used for.
> > > The following contexts will not have an extension slot anymore (they
> > > were not used before): script, catch and builtin contexts.
> > > Eval and function contexts only have the extension slot if they
> > > contain a sloppy eval.
> > >
> > > Bug: v8:9744
> > > Change-Id: I8ca56c22fa02437bbac392ea72174ebfca80e030
> > > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863191
> > > Commit-Queue: Victor Gomes <victorgomes@google.com>
> > > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> > > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> > > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> > > Auto-Submit: Victor Gomes <victorgomes@google.com>
> > > Cr-Commit-Position: refs/heads/master@{#64372}
> >
> > TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org
> >
> > Bug: v8:9744
> > Change-Id: I0749cc2d8f59940c25841736634a70047116d647
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1869192
> > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> > Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> > Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> > Auto-Submit: Victor Gomes <victorgomes@google.com>
> > Cr-Commit-Position: refs/heads/master@{#64380}
> 
> TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org
> 
> Bug: v8:9744
> Change-Id: I621ffe98722f8c4defaf277b8d1666484ba2963f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1872400
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Commit-Queue: Victor Gomes <victorgomes@google.com>
> Cr-Commit-Position: refs/heads/master@{#64451}

TBR=ulan@chromium.org,jgruber@chromium.org,petermarshall@chromium.org,leszeks@chromium.org,verwaest@chromium.org,victorgomes@google.com

Change-Id: I99a71180c6a00a87478867a8210ff9ceb46cb3ee
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9744
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1872405Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64453}

This is a reland of c48096d4

Original change's description:
> Reland "[runtime] Remove extension slots from context objects"
>
> This is a reland of c07c02e1
>
> Original change's description:
> > [runtime] Remove extension slots from context objects
> >
> > Context objects have an extension slot, which contains further
> > additional data that depends on the type of the context.
> >
> > This CL removes the extension slot from contexts that don't need
> > them, hence reducing memory.
> >
> > The following contexts will still have an extension slot: native,
> > module, await, block and with contexts. See objects/contexts.h for
> > what the slot is used for.
> > The following contexts will not have an extension slot anymore (they
> > were not used before): script, catch and builtin contexts.
> > Eval and function contexts only have the extension slot if they
> > contain a sloppy eval.
> >
> > Bug: v8:9744
> > Change-Id: I8ca56c22fa02437bbac392ea72174ebfca80e030
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863191
> > Commit-Queue: Victor Gomes <victorgomes@google.com>
> > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> > Auto-Submit: Victor Gomes <victorgomes@google.com>
> > Cr-Commit-Position: refs/heads/master@{#64372}
>
> TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org
>
> Bug: v8:9744
> Change-Id: I0749cc2d8f59940c25841736634a70047116d647
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1869192
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> Auto-Submit: Victor Gomes <victorgomes@google.com>
> Cr-Commit-Position: refs/heads/master@{#64380}

TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org

Bug: v8:9744
Change-Id: I621ffe98722f8c4defaf277b8d1666484ba2963f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1872400Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@google.com>
Cr-Commit-Position: refs/heads/master@{#64451}

This reverts commit c48096d4.

Reason for revert: Flaky bot failures (https://bugs.chromium.org/p/v8/issues/detail?id=9744#c9)

Original change's description:
> Reland "[runtime] Remove extension slots from context objects"
> 
> This is a reland of c07c02e1
> 
> Original change's description:
> > [runtime] Remove extension slots from context objects
> >
> > Context objects have an extension slot, which contains further
> > additional data that depends on the type of the context.
> >
> > This CL removes the extension slot from contexts that don't need
> > them, hence reducing memory.
> >
> > The following contexts will still have an extension slot: native,
> > module, await, block and with contexts. See objects/contexts.h for
> > what the slot is used for.
> > The following contexts will not have an extension slot anymore (they
> > were not used before): script, catch and builtin contexts.
> > Eval and function contexts only have the extension slot if they
> > contain a sloppy eval.
> >
> > Bug: v8:9744
> > Change-Id: I8ca56c22fa02437bbac392ea72174ebfca80e030
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863191
> > Commit-Queue: Victor Gomes <victorgomes@google.com>
> > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> > Auto-Submit: Victor Gomes <victorgomes@google.com>
> > Cr-Commit-Position: refs/heads/master@{#64372}
> 
> TBR=verwaest@chromium.org,jgruber@chromium.org,ulan@chromium.org,leszeks@chromium.org,petermarshall@chromium.org
> 
> Bug: v8:9744
> Change-Id: I0749cc2d8f59940c25841736634a70047116d647
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1869192
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> Auto-Submit: Victor Gomes <victorgomes@google.com>
> Cr-Commit-Position: refs/heads/master@{#64380}

TBR=ulan@chromium.org,jgruber@chromium.org,petermarshall@chromium.org,leszeks@chromium.org,verwaest@chromium.org,victorgomes@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:9744
Change-Id: Ia58067b41f1eb5880a52b36ead754d7190ff7f6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1871922Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64424}