This reverts commit cc047635.
The CL was reverted due to a missing DEPS mirror.

Original issue's description:
> ARM64: Add NEON support
>
> Add assembler, disassembler and simulator support for NEON in the ARM64 backend.
>
> BUG=
>
> Review-Url: https://codereview.chromium.org/2622643005
> Cr-Commit-Position: refs/heads/master@{#44306}

BUG=

Review-Url: https://codereview.chromium.org/2812573003
Cr-Commit-Position: refs/heads/master@{#44652}

TBR=ishell@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2818773002
Cr-Commit-Position: refs/heads/master@{#44651}

Taking the slow runtime path for every non-internalized string key
can be avoided by doing optimistic string table lookups: if there
is a matching entry, use that; if there isn't, then no existing
object has a property with that name.
The hashing/internalizing logic is in C++ and called directly.

Review-Url: https://codereview.chromium.org/2811333002
Cr-Commit-Position: refs/heads/master@{#44650}

https://github.com/tc39/proposal-async-iteration/commit/e3246ad69cc6f83b34bdd3451c3c6abce37fd1f3
removed some redundancies in yield and yield*.

In particular:
- AsyncGeneratorRawYield becomes unnecessary, and is deleted in this CL
- Parser::RewriteYieldStar() is updated to perform the IteratorValue() algorithm as appropriate

BUG=v8:6187, v8:5855
R=rmcilroy@chromium.org, adamk@chromium.org, littledan@chromium.org, vogelheim@chromium.org

Change-Id: I05e8429b9cbd4531c330ee53a05656b90162064c
Reviewed-on: https://chromium-review.googlesource.com/471806Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#44649}

R=tebbi@chromium.org

Change-Id: I28cdf18616e16a681e2cab3f36263f3c09953b8b
Reviewed-on: https://chromium-review.googlesource.com/476612
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44648}

Currently we count optimizations to decide to disable optimization, and
count deopts to detect this decision and allow re-enabling optimizations
after a while.

However, throwing out TurboFan OSR code and GC optimized code evictions
do not count as deopts, which means that the optimization count
increases without increasing the deopt count. This increased optimization
count disables further optimization -- which is bad, because these are
not "true" deopts -- and can stop the optimization from being re-enabled,
because the deopt count can't go high enough.

Instead, we now only ever look at deopts to disable/re-enable
optimization, and opt counts are only used for naming log files and in
tests.

Change-Id: I0c7d6be497545449a38cf952cd2f007ee51982ba
Reviewed-on: https://chromium-review.googlesource.com/468811
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44647}

This option doesn't work for ARM any more.

BUG=

Review-Url: https://codereview.chromium.org/2816703002
Cr-Commit-Position: refs/heads/master@{#44646}

If the new.target passed to the Array constructor cannot be a Proxy,
then we know that the Array constructor cannot trigger any observable
side-effects.

R=jarin@chromium.org
BUG=v8:6262

Review-Url: https://codereview.chromium.org/2821453002
Cr-Commit-Position: refs/heads/master@{#44645}

The JSArgumentsObject::length representation is initially Smi, so we can
record that on the initial map and use it to optimize the accesses in
TurboFan based on that. Similar for JSSloppyArgumentsObject::caller.

BUG=v8:6262
R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2810333004
Cr-Commit-Position: refs/heads/master@{#44644}

R=jochen@chromium.org

Review-Url: https://codereview.chromium.org/2812603002
Cr-Commit-Position: refs/heads/master@{#44643}

TBR=machenbach@chromium.org,vogelheim@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2814993006 .
Cr-Commit-Position: refs/heads/master@{#44642}

This is requested for Node.js N-API. Tests to be added.

Review-Url: https://codereview.chromium.org/2812613002
Cr-Commit-Position: refs/heads/master@{#44641}

Previously, we would only consider it if it pointed to a full-code JS function.
Thus we could miss both optimized functions and bytecode handlers if they
called frame-less code.

Review-Url: https://codereview.chromium.org/2822433002
Cr-Commit-Position: refs/heads/master@{#44640}

This fixes the validation of "|0" annotations of call sites that are
used to indicate a "signed" return type of functions. We use lookahead
during call validation and request deferred validation as part of the
actual OR-expression. Special care has to be taken to get precedence
levels of all involved operators right.

R=clemensh@chromium.org
TEST=mjsunit/asm/call-annotation
BUG=v8:6183

Change-Id: If0586f669e7cee26a13425b0fd9f41098e852d68
Reviewed-on: https://chromium-review.googlesource.com/475871
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44639}

The condition only applies in unicode mode, where any lone surrogates
are desugared into a character class (and will not be considered in this
optimization). Non-unicode mode treats lone surrogates exactly like
any other codepoint.

BUG=chromium:711092

Review-Url: https://codereview.chromium.org/2808403006
Cr-Commit-Position: refs/heads/master@{#44638}

In eval scripts, the source code position can be 0 rather
than greater than 0.

Add regression test.

Drive-by fix: unrelated typo.

Bug: 707223
Change-Id: If52c0736daac3ad42ac6d324eb8ec5f1798f6f5a
Reviewed-on: https://chromium-review.googlesource.com/476630Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Franziska Hinkelmann <franzih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44637}

This issue was fixed in VisitWord64And in 2f8ad11f. Port the fix to
VisitWord32And.

BUG=

Review-Url: https://codereview.chromium.org/2815853002
Cr-Commit-Position: refs/heads/master@{#44636}

Bug: chromium:710428,v8:6248
Change-Id: I70430d5a200199563bf5468a6cc80614307f63e6
Reviewed-on: https://chromium-review.googlesource.com/474847Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44635}

When optimizing calls to get Object.prototype.__proto__ in
JSCallReducer, we can also consume unreliable receiver map
information, as long as the receiver maps are stable. In
that case we also need to install proper stability dependencies.

BUG=chromium:711195,v8:5267,v8:6241
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2816993002
Cr-Commit-Position: refs/heads/master@{#44634}

This CL implements the proposed change to show information about
WebAssembly values and call frames via the inspector interface.
Each interpreted WebAssembly frame will have two scopes: A global scope
showing information about the memory (to be extended for globals), and
a local scope showing information about parameters, local variables, and
stack values.
Names of local variables will be added later.

R=ahaas@chromium.org, yangguo@chromium.org
BUG=v8:6245,v8:5822

Change-Id: I0a35fddd0a353933c86adf62083233b08098a2c7
Reviewed-on: https://chromium-review.googlesource.com/474865
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44633}

This fixes the existing lowering of {JSGetSuperConstructor} nodes to
unconditional throws. The above operator is marked as {kNoWrite} but
runtime calls are not marked as such. Any deoptimizing operation after
the throw would not be able to find a valid {Checkpoint}. We remove the
lowering case in question.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-6248
BUG=v8:6248

Change-Id: I22c922947336254502f698b02f944cf35dd8688a
Reviewed-on: https://chromium-review.googlesource.com/476570Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44632}

When the incoming value to ChangeFloat64ToTagged is in Smi range, we
represent it as Smi instead of a HeapNumber. This addresses a range of
problems where TurboFan unnecessarily deoptimizes because an operation
learned Smi feedback in Ignition, but was then confronted with a tagged
HeapNumber in TurboFan, just because the value was also represented as
unboxed double somewhere in the meantime.

BUG=v8:6256
R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2815283002
Cr-Commit-Position: refs/heads/master@{#44631}

This patch delays the DisposeModuleEmbedderData call for 
the interative shell case until we exit the RunShell function.

Bug: v8:5785
Change-Id: I01ff76000882cd1d6801fefc9ea3770c3f38c83b
Reviewed-on: https://chromium-review.googlesource.com/476024
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44630}

Adds some benchmarks copied from v8:4762.

BUG=v8:4762, v8:5460
R=adamk@chromium.org

Change-Id: I0b96080042781c2c46c0c8a3896a921bde97c1e5
Reviewed-on: https://chromium-review.googlesource.com/475934Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#44629}

R=joransiu@ca.ibm.com, bjaideep@ca.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/2815903002
Cr-Commit-Position: refs/heads/master@{#44628}

Port a7c4e778

Original Commit Message:

    This change mirrors the semantics for derived class constructors. This
    change doesn't affect non class constructors.

    This change could potentially break web compat. More details:
    https://github.com/tc39/ecma262/pull/469

R=gsathya@chromium.org, joransiu@ca.ibm.com, bjaideep@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2815873003
Cr-Commit-Position: refs/heads/master@{#44627}

It's required by the spec -- and observable -- that the index be validated
before the conversion of the value(s) via ToInteger.

The previous implementation also had an old test for validating the atomic
index, which has now been switched to ToIndex.

This also exposed an issue in the ia32 code generator: cmpxchg_b requires a
byte register, but the ia32 instruction selector was ensuring that the
new_value was a byte register, not the TempRegister. This change forces the
temp register to use edx, which always can be used as a byte register (dl).
This is the same behavior as currently used in UseByteRegister.

BUG=v8:4614
R=jarin@chromium.org,jkummerow@chromium.org

Review-Url: https://codereview.chromium.org/2814753003
Cr-Commit-Position: refs/heads/master@{#44626}

When doing VS 2017 official builds of some targets, including
mksnapshot.exe, a warning about a buffer overrun is shown. After
analysis and discussion with Microsoft it was decided that this warning
is spurious. The warning is:

    warning C4789: buffer 'key' of size 16 bytes will be overrun; 4
    bytes will be written starting at offset 16

Despite the certain language "4 bytes *will* be written..." it is in
fact a heuristic based warning. Suppressing it at this point in the
inlining stack appears to avoid the issues.

R=hablich@chromium.org
BUG=v8:6068

Review-Url: https://codereview.chromium.org/2804033005
Cr-Commit-Position: refs/heads/master@{#44625}

We currently store it in parent stack trace but stacks with the same parent can have different creations stacks.

BUG=v8:6189
R=dgozman@chromium.org

Review-Url: https://codereview.chromium.org/2807273002
Cr-Commit-Position: refs/heads/master@{#44624}

The arm64 MacroAssembler expects buffer_size to be an unsigned, not a
size_t.

BUG=chromium:710913

Review-Url: https://codereview.chromium.org/2818513002
Cr-Commit-Position: refs/heads/master@{#44623}

Usually program doesn't contain a lot of different stack frames in collected stack trace.

BUG=v8:6189
R=yangguo@chromium.orr
TBR=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2788413004
Cr-Commit-Position: refs/heads/master@{#44622}

Optimizations are supposed to be disabled in our stack-trace code when
building with VC++. However the check used #if defined(COMPILER_MSVC)
when that is never defined in v8. The correct define in v8 is
V8_CC_MSVC.

R=hablich@chromium.org

Review-Url: https://codereview.chromium.org/2800043003
Cr-Commit-Position: refs/heads/master@{#44621}

gdb_index is not in declare_args() and has no effect.

NOTRY=true

Change-Id: I88a9558937aa8fea30ab246899bea4a123947f82
Reviewed-on: https://chromium-review.googlesource.com/475772
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44620}

The BytecodePipeline is no longer used by any optimizers, so remove it and
connect the BytecodeArrayBuilder directly to the BytecodeWriter.

Also remove some functions from BytecodeNode which are no longer used.

BUG=v8:6194

Change-Id: Id2ec94ff1d4db41b108a778100459283fbb2256c
Reviewed-on: https://chromium-review.googlesource.com/471528Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44619}

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2800813002
Cr-Commit-Position: refs/heads/master@{#44618}

This relands commit a79f9031.

Original change's description:
> [Interpreter] Unify approach to building interpreter handler and Turbofan stubs.
> 
> Moves interpreter-generator.cc to a similar model of building handlers as
> Turbofan stubs elsewhere, to simplify moving code between stubs / builtins and
> bytecode handlers. This removes the "__" hack from the Interpreter generator
> code.
> 
> Also make SetBytecodeOffset private to InterpreterAssembler and make 
> LdaImmutable[Current]ContextSlot and Lda[Current]ContextSlot share
> handlers since they are identical.
> 
> Change-Id: I9e91e7d37c2ea75513e4dcc3b95b4bb6517f83da
> Reviewed-on: https://chromium-review.googlesource.com/471987
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#44534}
> 
TBR=rmcilroy@chromium.org,jkummerow@chromium.org,machenbach@chromium.org,cbruni@chromium.org,leszeks@chromium.org,v8-reviews@googlegroups.com,ishell@chromium.org

Change-Id: I282fe5582f681ccb0642537a70f89185558ee195
Reviewed-on: https://chromium-review.googlesource.com/474755Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44617}

This reverts commit b9194e93.

Reason for revert: Makes old pipeline flaky with custom snapshot:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20custom%20snapshot%20-%20debug/builds/14049

Original change's description:
> [heap-verification] Increase verification for arguments objects
> 
> BUG: v8:6251
> Change-Id: I8a6dd528656a69c7910770acaf2133830b60c291
> Reviewed-on: https://chromium-review.googlesource.com/475651
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#44609}

TBR=jkummerow@chromium.org,cbruni@chromium.org,v8-reviews@googlegroups.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: Iedfdad290bf4f5f6ec2534e8c5378a7cc195db82
Reviewed-on: https://chromium-review.googlesource.com/475719Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44616}

Unfortunately, this test cannot test that a function was really skipped (i.e.,
not parsed).

BUG=v8:5516

Change-Id: I8db5027d2216a95cc012ceae8e17554095cc1d4f
Reviewed-on: https://chromium-review.googlesource.com/457037Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44615}

Revert of [wasm] instantiate expressed in terms of compile (patchset #6 id:140001 of https://codereview.chromium.org/2806073002/ )

Reason for revert:
Roll blocker: https://bugs.chromium.org/p/chromium/issues/detail?id=710824

Original issue's description:
> [wasm] instantiate expressed in terms of compile
>
> Today, the semantics of:
>
> WebAssembly.instantiate
>
> and
>
> WebAssembly.compile().then(new WebAssemblyInstance)
>
> are subtly different, to the point where attempting the proposed
> change uncovered bugs.
>
> In the future, it's possible that .instantiate actually have different
> semantics - if we pre-specialized to the provided ffi, for example.
> Right now that's not the case.
>
> This CL:
> - gets our implementation closer to what developers may write using
> the compile -> new Instance alternative, in particular wrt promise
> creation. By reusing code paths, we uncover more bugs, and keep
> maintenance cost lower.
>
> - it gives us the response-based WebAssembly.instantiate implicitly.
> Otherwise, we'd need that same implementation on the blink side. The
> negative is maintenance: imagine if the bugs I mentioned could only be
> found when running in Blink.
>
> BUG=chromium:697028
>
> Review-Url: https://codereview.chromium.org/2806073002
> Cr-Commit-Position: refs/heads/master@{#44592}
> Committed: https://chromium.googlesource.com/v8/v8/+/7829af3275ff4644a2d0a1270abe1a1e4415e9fb

TBR=bradnelson@chromium.org,ahaas@chromium.org,adamk@chromium.org,mtrofin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:697028

Review-Url: https://codereview.chromium.org/2810203002
Cr-Commit-Position: refs/heads/master@{#44614}

The biggest problem is isolate.h (this CL doesn't solve that yet).

BUG=v8:5294

Change-Id: I56b32109f501c48facd99cd12ca6c8f427e188a9
Reviewed-on: https://chromium-review.googlesource.com/471487Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44613}