This migrates the JSEntryStub to three dedicated builtins:

JSEntry
JSConstructEntry
JSRunMicrotasksEntry

Drive-by: Tweaks to make the code isolate-independent (e.g. using the
correct macro assembler method to load and store external references
through the kRootRegister).
Drive-by: The context slot on x64/ia32 must be set up after
kRootRegister is initialized, so we first reserve the slot and later
load its value.
Drive-by: Update all remaining comments referencing JSEntryStub.

Bug: v8:7777
Change-Id: Ie3ba17ffb3bde6f18ec1d26d778b258719b2d4ef
Reviewed-on: https://chromium-review.googlesource.com/c/1365275Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58088}

Bug: v8:8477, v8:8238
Change-Id: I8170911d27b605a5befe959af16212c870104a2b
Reviewed-on: https://chromium-review.googlesource.com/c/1366735Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58087}

Bug: v8:8477, v8:8238
Change-Id: If776225f8949ba84fa17de333b4f14188c93a93d
Reviewed-on: https://chromium-review.googlesource.com/c/1366615Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58086}

This is preparation to switch swarming client.

Bug: chromium:894045, chromium:907585
Change-Id: I3cd5eec0ed8a81eefbac0061f0ee0eb38f5bfd7c
Reviewed-on: https://chromium-review.googlesource.com/c/1365212Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58085}

Now that `do` expressions have been removed [1], we should remove the
corresponding golden file as well.

[1]: https://chromium.googlesource.com/v8/v8/+/58988c6c6395788799057ab8a0676d0534c46c14

Change-Id: I4a6908d4d53b2bce1d9f2d616c672b4caf15adac
Reviewed-on: https://chromium-review.googlesource.com/c/1365283Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58084}

TBR=santa

Change-Id: Id624d0e64fcc1c8daf52a032cbb2daf12493e26d
Reviewed-on: https://chromium-review.googlesource.com/c/1367445Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58083}

The removed tests should be later covered by v8:8556

Bug: v8:5751, v8:8556
Change-Id: Iea5450564ab4f85256f1aa76fb09d7e6704f9bd3
Reviewed-on: https://chromium-review.googlesource.com/c/1355634Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58082}

Simplified test for default locale under test/intl
Remove GetDefaultLocale from runtime
Move Intl::DefaultLocale from intl-object.h to
internal function inside intl-object.cc

Bug: v8:5751
Change-Id: I885abf30ff33d5213ee99c07ac1e92d3c5065d8b
Reviewed-on: https://chromium-review.googlesource.com/c/1358022Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58081}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/9fee3d5..9e9ea82

Rolling v8/buildtools: https://chromium.googlesource.com/chromium/buildtools/+log/04161ec..7d88270

Rolling v8/test/wasm-js/data: https://chromium.googlesource.com/external/github.com/WebAssembly/spec/+log/76d26bb..89ae39c

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/a8f4725..5d7bcad

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/9875e18..f94f910

TBR=machenbach@chromium.org,hablich@chromium.org,sergiyb@chromium.org

Change-Id: I7825688d990209a62fb5aca120d96b1bf38c5c17
Reviewed-on: https://chromium-review.googlesource.com/c/1367127Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#58080}

Bug: v8:7834
Change-Id: I2b1444eded3d2917bf67f5077f35daccdbbbb951
Reviewed-on: https://chromium-review.googlesource.com/c/1367125Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58079}

This is a reland of 0e8f20d2

Original change's description:
> [wasm] fix js-api interface
> 
> Make sure WebAssembly's js-api exposes the correct attributes: writable,
> enumerable and configurable.
> 
> Bug: v8:8319
> Change-Id: I427533159d7975a42c0c5cb1babdc8a61f8198b5
> Reviewed-on: https://chromium-review.googlesource.com/c/1351002
> Commit-Queue: Adam Klein <adamk@chromium.org>
> Reviewed-by: Adam Klein <adamk@chromium.org>
> Reviewed-by: Ben Smith <binji@chromium.org>
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58053}

Bug: v8:8319
Change-Id: I2d0af568edab295ad8c01b64e588bbabf89bd251
Reviewed-on: https://chromium-review.googlesource.com/c/1365273Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58078}

This reverts commit d9fbfeb8.

Reason for revert: see bug.
Bug: 906847

Original change's description:
> inspector: return [[StableObjectId]] as internal property
> 
> This property might be useful for fast '===' check.
> 
> R=​dgozman@chromium.org,yangguo@chromium.org
> 
> Bug: none
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
> Change-Id: Iabc3555ce1ec2c14cf0ccd40b7d964ae144e7352
> Reviewed-on: https://chromium-review.googlesource.com/1226411
> Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56095}

TBR=dgozman@chromium.org,yangguo@chromium.org,kozyatinskiy@chromium.org,jgruber@chromium.org

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

Bug: none
Change-Id: I68c700b7b8fd0a015f099460c15665d74e4da183
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Reviewed-on: https://chromium-review.googlesource.com/c/1363558Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58077}

because attempt to decompress the off-heap map slot will fail.

Bug: v8:7703
Change-Id: Iad3884fb95ccb17b2992d190acb5914062a0e8f4
Reviewed-on: https://chromium-review.googlesource.com/c/1365286Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58076}

to make TSAN happy.

Bug: v8:8518
Change-Id: I1c7291cc6035c7e88758d867cb74467c59e95ef1
No-Tree-Checks: true
Reviewed-on: https://chromium-review.googlesource.com/c/1365285Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58075}

Since RO_SPACE strings cannot be written to after creation, they cannot
be internalized later. This adds checks to normal string construction
methods that they are not created with TENURED_READ_ONLY.

Also changes the Symbol construction in setup-heap-internal.cc to use
internalized strings, which increases the number of internalized
RO_SPACE strings from 490 to 514 (915 including OLD_SPACE).

Bug: chromium:911416
Change-Id: I222ff883e98f3a2f4ce70d369f22273f5c9edb0b
Reviewed-on: https://chromium-review.googlesource.com/c/1365279Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58074}

which will require different handling for compressed pointers case.

Bug: v8:8518
Change-Id: I99cb103bad57b134ecb8d7dd7018cf16ed3d8f25
Reviewed-on: https://chromium-review.googlesource.com/c/1365272Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58073}

The main change is about tracking typed slots locally in
each concurrent marking thread.

This generalizes the old LiveBytesMap to MemoryChunkData, which
now contains the live bytes and the typed slots.

With that in place it is straightforward to mark code concurrently.

Bug: v8:8459
Change-Id: I103fff0ad39beadea5151a1d8519f5d3c6602e58
Reviewed-on: https://chromium-review.googlesource.com/c/1337747
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58072}

There is no fast path for 0-length substrings, which implied runtime
calls for some of the trickier types of strings (such as non-flat
cons-strings). This made for a big performance gap between
String.p.slice and String.p.substring for those inputs.

This CL just adds the 0-length shortcut in CSA implementation
of SubString.

Here is an example where it makes difference:

  let s = "abcdefghijkalmnopqrst";
  let a = "";

  console.time("Substring");
  for (let i = 0; i < 100000; i++) {
    s += "0";
    a += s.substring(0, 0);
  }
  console.timeEnd("Substring");

Before this change:
> console.timeEnd: Substring, 640.308000

After this change:
> console.timeEnd: Substring, 13.242000

For completeness, here is the time for slice:
> console.timeEnd: Slice, 13.142000

This also recovers performance in the jsdom library, as
observed in https://github.com/jsdom/jsdom/issues/2350.

Bug: v8:6730
Change-Id: I7d2127e4506a86ec2a7ed378293476c3699dc47a
Reviewed-on: https://chromium-review.googlesource.com/c/1365282
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58071}

Bug: v8:8394
Change-Id: If9af9f3c79e442f6e384934e005ae5d82b0d358b
Reviewed-on: https://chromium-review.googlesource.com/c/1365277Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58070}

Fixes https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20noembed%20-%20debug/781.
Failing since https://crrev.com/c/1360630.

Tbr: yangguo@chromium.org
Bug: v8:7777
Change-Id: Ia9adfa9340087dfcd74c966c40a54176081f6933
Reviewed-on: https://chromium-review.googlesource.com/c/1365276Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58069}

This replaces Runtime_RunMicrotasks with Runtime_PerformMicrotaskCheckpoint.

RunMicrotasks forcibly runs Microtasks even when the microtasks are suppressed,
and may causes nested Microtasks in a problematic way. E.g. that confuses
v8::MicrotasksScope::IsRunningMicrotasks() and GetEnteredOrMicrotaskContext().

OTOH, PerformMicrotaskCheckpoint() doesn't run cause the failure as it
respects the microtask suppressions.

As all existing tests don't call RunMicrotasks() in the suppressed situation
(like Promise.resolve().then(()=>{%RunMicrotasks();})), this change should
not affect to these tests.

Change-Id: Ib043a0cc8e482e022d375084d65ea98a6f54ef3d
Reviewed-on: https://chromium-review.googlesource.com/c/1360095Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58068}

Bug: v8:8525
Change-Id: I42764afbb419825fe6af504a641a78dbb127f30c
Reviewed-on: https://chromium-review.googlesource.com/c/1355629
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58067}

Currently, if we lower to a pure computation that is unreachable because
of some runtime check, we just rename it with DeadValue. This is
problematic if the pure computation gets later eliminated - that allows
the DeadValue node float above the check that makes it dead. As we
conservatively lower DeadValues to debug-break (i.e., crash), we
might induce crash where we should not.

With this CL, whenever we lower an impossible effectful node (i.e., with
Type::None) to a pure node in simplified lowering, we insert an
Unreachable node there (pinned to the effect chain) and mark the
impossible node dead (and make it depend on the Unreachable node).

Bug: chromium:910838
Change-Id: I218991c79b9e283a9dd5beb4d3f0c4664be76cb2
Reviewed-on: https://chromium-review.googlesource.com/c/1365274Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58066}

In preparation for converting JSEntry into a builtin. The root register
used to be initialized by an embedded external reference, which is not
isolate-independent. Pass in its value explicitly instead.

Tbr: clemensh@chromium.org
Bug: v8:7777
Change-Id: If9d20cb193af175bd1cf58e5826bdf6f397869ad
Reviewed-on: https://chromium-review.googlesource.com/c/1363139Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58065}

A spec change to simplify IsRegExp has been proposed:

https://github.com/tc39/ecma262/pull/1318

This CL adds use counters for cases in which the spec change would
alter behavior:

1. o[@@match] is trueish but o is not a JSRegExp
2. o[@@match] is falseish (but not undefined) and o is a JSRegExp

This is the V8 side of required changes.
The Chromium-side CL: https://crrev.com/c/1360730

Drive-by: TNodeify IsRegExp.

Tbr: yangguo@chromium.org
Bug: v8:8522
Change-Id: I3766e02977f256a80d0e59472d3bafa9c692af9e
Reviewed-on: https://chromium-review.googlesource.com/c/1360630Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58064}

This addresses follow-up comments to https://crrev.com/c/1354887/.

Use DCHECKs instead of CHECKs and make the branch order consistent
across architectures.

Bug: v8:7777
Change-Id: I5c3f8f5ac97b55fa80662bc211aff7833ff12bfa
Reviewed-on: https://chromium-review.googlesource.com/c/1362912
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58063}

TBR=santa

Change-Id: If6722b455219d5113ddbfe1a97e9178e7fad63c9
Reviewed-on: https://chromium-review.googlesource.com/c/1365271Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58062}

This reverts commit 0e8f20d2.

Reason for revert: Breaks layout tests, blocks roll: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux-blink-rel/3047

Original change's description:
> [wasm] fix js-api interface
> 
> Make sure WebAssembly's js-api exposes the correct attributes: writable,
> enumerable and configurable.
> 
> Bug: v8:8319
> Change-Id: I427533159d7975a42c0c5cb1babdc8a61f8198b5
> Reviewed-on: https://chromium-review.googlesource.com/c/1351002
> Commit-Queue: Adam Klein <adamk@chromium.org>
> Reviewed-by: Adam Klein <adamk@chromium.org>
> Reviewed-by: Ben Smith <binji@chromium.org>
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58053}

TBR=binji@chromium.org,adamk@chromium.org,gdeepti@chromium.org,ssauleau@igalia.com

Change-Id: I16fa44a0e79020850613751ae45a68d67602166d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8319
Reviewed-on: https://chromium-review.googlesource.com/c/1365270Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58061}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/9c85c83..9fee3d5

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/58f2981..a8f4725

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/f28ef98..9875e18

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/0dea619..f6641a3

Rolling v8/tools/luci-go:infra/tools/luci/isolate/${platform}: https://chrome-infra-packages.appspot.com/infra/tools/luci/isolate/${platform}/+log/git_rev..git_rev

TBR=machenbach@chromium.org,hablich@chromium.org,sergiyb@chromium.org

Change-Id: I944970e96d4db2531431643cf54d3369ea977b49
Reviewed-on: https://chromium-review.googlesource.com/c/1364711
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#58060}

Change-Id: Id221faecc9873cb0dbbd89777e055884158dbfb3
Reviewed-on: https://chromium-review.googlesource.com/c/1364370Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58059}

The prefix size is read from the Derived class.
The hash code of the object will be stored in this prefix.

Change-Id: I15646701c9bab99b8aed39ea9ad8ae03f6d605ed
Bug: v8:6443, v8:7569
Reviewed-on: https://chromium-review.googlesource.com/c/1337586
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58058}

Bug: v8:8518
Change-Id: I39db0adbd84627491bcb653b90de724eb988d383
Reviewed-on: https://chromium-review.googlesource.com/c/1363145
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58057}

and
1) make them represent kSystemPointerSize-sized off-heap slots,
2) reintroduce XxxSlots as an on-heap kTaggedSize-sized slots (for now they
   are just aliases to respective FullXxxSlots).

Bug: v8:8518
Change-Id: I8a9177562308bd9420b1eebca959cc52ceaa628e
Reviewed-on: https://chromium-review.googlesource.com/c/1363144
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58056}

A WasmModuleObject represents an instance of WebAssembly.Module. It is
called WasmModuleObject internally, so also use that name externally.

We still have a typedef for WasmCompiledModule which will be deprecated
once chromium has been updated to use WasmModuleObject.

R=titzer@chromium.org, adamk@chromium.org

Bug: v8:8238, chromium:912031
Change-Id: I2d7708d4dc183cb4f4714f741b1ea0c153014430
Reviewed-on: https://chromium-review.googlesource.com/c/1362048Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58055}

Port cfdf6ff8

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

Change-Id: I8821b82f181a44b70272d770703136983d821d1c
Reviewed-on: https://chromium-review.googlesource.com/c/1363449Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#58054}

Make sure WebAssembly's js-api exposes the correct attributes: writable,
enumerable and configurable.

Bug: v8:8319
Change-Id: I427533159d7975a42c0c5cb1babdc8a61f8198b5
Reviewed-on: https://chromium-review.googlesource.com/c/1351002
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ben Smith <binji@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58053}

Bug: v8:7793
Change-Id: I12aae5d61a21f3e6e010e07622fe0d01a5ba03eb
Reviewed-on: https://chromium-review.googlesource.com/c/1344118
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58052}

A fancy new stdlib addition for creating JSObjects from a collection of
key/value pairs, coming soon to a javascript runtime near you.

BUG=v8:8021
R=gsathya@chromium.org, adamk@chromium.org

Change-Id: I5eb1dea75bfef009281eef9864c8c0226af4f1fc
Reviewed-on: https://chromium-review.googlesource.com/c/1363293Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#58051}

Even though descriptor arrays are references by maps in the old
generation, they seems to be short living in benchmarks.

This fixes perf regressions introduced in 1ad0cd56.

Bug:chromium:911073,chromium:910567,chromium:910443,

Change-Id: Iaf933d409e72c6c26df48f6435f9543224ea7d67
Reviewed-on: https://chromium-review.googlesource.com/c/1363146Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58050}

Intrinsic changes:

- Rename %RawCast to %RawObjectCast and add error checking so that it
  only applies to subtypes of Objects.

- Add %RawPointerCast, which is similar to %RawObjectCast but must be
  used for all subtypes of RawPtr.

- Add %RawConstexprCast, which allows one constexpr to be be cast to
  another at compile time. It translate to an appropriate static_cast
  in the generated code

- Add %FromConstexpr, which handles most of the standard cases of
  generating XXXConstant CSA nodes from constexpr constants. It uses
  either SmiConstant, NumberConstant, StringConstant, IntPtrConstant
  or Int32Constant, depending on the cast-to type generic <To> type.

- Add support for intrinsics that return constexpr results.

Cleanup:

- Turn FromConstexpr into a generic with two generic types, a <To> and
  a <From> type. Most FromConstexpr can use the new %FromConstexpr
  intrinsic rather than provide an explicit implementation.

Bug: v8:7793
Change-Id: Icab5db16d203034ec157fa3ad5157d10c7dc8464
Reviewed-on: https://chromium-review.googlesource.com/c/1357049
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58049}