This is a reland of 7f67cbd4

Original change's description:
> [turbofan] More brokerization in JSCreateLowering.
> 
> Brokerized ReduceJSCreateEmptyLiteralObject and added the scope
> for ReduceJSCreateLiteralArrayOrObject.
> 
> Bug: v8:7790
> Change-Id: Ife34a6b610678a3fe24152151cf343400ee515bd
> Reviewed-on: https://chromium-review.googlesource.com/1140306
> Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54507}

Bug: v8:7790
Change-Id: Ia79ff9ef49c727155a9c476268234e56d2cc9fcb
Reviewed-on: https://chromium-review.googlesource.com/1142984
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54538}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/e4fb293..abdb548

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/f5342c4..26d6aff

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/302bb84..f9afc77

Rolling v8/third_party/fuchsia-sdk: https://chromium.googlesource.com/chromium/src/third_party/fuchsia-sdk/+log/976ce5e..6215064

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

Change-Id: Ib6d7529ad818b0737ce780a70e5e38e6226a457c
Reviewed-on: https://chromium-review.googlesource.com/1142901
Commit-Queue: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Reviewed-by: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#54537}

The previous change to futex.js will spawn too many workers in d8 in
some test configurations, which will throw an error.

This CL works around that by spawning fewer workers for the
Atomics.notify tests.

TBR=adamk@chromium.org

Bug: v8:7338
Change-Id: I0f3583781e5352b4d6672d43a087dc56d920122d
Reviewed-on: https://chromium-review.googlesource.com/1142895Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: Ben Smith <binji@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54536}

Turbofan support for property loads from module namespace objects
has been tested by the test/js-perf-tests/Modules/basic-namespace
benchmark, but so far not by the mjsunit suite. This CL adds such
a test.
This is a follow-up to 8d7379c0.

Change-Id: I3c4183d761693199e6bc8740b812279efcd791a0
Reviewed-on: https://chromium-review.googlesource.com/1142594Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54535}

At the May 2018 TC39 meeting, they decided to rename Atomics.wake to
Atomics.notify. This change adds Atomics.notify as an alias, but does
not remove Atomics.wake, which will be removed later.

This allows for embedders to use either name to prevent
breaking tests. When the tests are switched over, we can remove
Atomics.wake.

Bug: v8:7883
Change-Id: If057ebff162bde975c6e1b60d83a4662f144e81f
Reviewed-on: https://chromium-review.googlesource.com/1142290
Commit-Queue: Ben Smith <binji@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54534}

- Modifies LinkageAllocator to understand aliasing on ARM.
- Adds ability to allocate SIMD registers too. Before, these would
  default to stack allocated.
- Modifies WasmCompiler to be platform-independent.

Bug: v8:7754
Change-Id: I0c4355a44a4f409053b51ff675521a465e38aeb8
Reviewed-on: https://chromium-review.googlesource.com/1141114Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54533}

This is a reland of 8d4572a2

Original change's description:
> [builtins] Add %IsTraceCategoryEnabled and %Trace builtins
>
> Adds the builtin Trace and IsTraceCategoryEnabled functions
> exposed via extra bindings. These are intended to use by
> embedders to allow basic trace event support from JavaScript.
>
> ```js
> isTraceCategoryEnabled('v8.some-category')
>
> trace('e'.charCodeAt(0), 'v8.some-category',
>       'Foo', 0, { abc: 'xyz'})
> ```
>
> Bug: v8:7851
> Change-Id: I7bfb9bb059efdf87d92a56a0aae326650730c250
> Reviewed-on: https://chromium-review.googlesource.com/1103294
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54121}

TBR=cbruni@chromium.org

Bug: v8:7851
Change-Id: Id063754b2834b3b6a2b2654e76e8637bcd6aa5f8
Reviewed-on: https://chromium-review.googlesource.com/1137071
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54532}

Avoid the C-call to switch the flag, just store to the address
directly. Since js-to-wasm wrappers are still isolate dependent,
we just store the address of the thread-local flag in the isolate
(in ThreadLocalTop) and update it if threads are switched.

R=ahaas@chromium.org, mstarzinger@chromium.org

Bug: chromium:862123, v8:5277
Change-Id: I9e8a40094f11a8b3ba6701dfa7fa026a2d052cb1
Reviewed-on: https://chromium-review.googlesource.com/1136299
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54531}

Bug: v8:5751

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I5e149a5d7aff486a31415ae9935461e275c867bd
Reviewed-on: https://chromium-review.googlesource.com/1112202
Commit-Queue: Brian Stell <bstell@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54530}

Bug: v8:7869
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I91bb1948a46249157e143733862c0eeefd15cb0d
Reviewed-on: https://chromium-review.googlesource.com/1137365
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54529}

TBR=sigurds@chromium.org

No-Try: true
Bug: v8:7953
Change-Id: I188c5b0501c2f0cbf8dacdec21f3e86ebec88cd7
Reviewed-on: https://chromium-review.googlesource.com/1142404Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54528}

Move brackets enclosing declarator in a couple of V8_DEPRECATE_SOON
cases so that the attribute is correctly placed.

I.e. should come after the class keyword and after a function signature
but before the body.

Also adds suppressions for a case where a replacement method calls
the deprecated method it replaces.

Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I490ff07a13552cf335186d64ca061f21ac4e8afc
Reviewed-on: https://chromium-review.googlesource.com/1140593Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54527}

ReadOnlyRoots means that some added Isolate parameters are no longer
needed. So, we can remove them.

This patch was generated mostly automatically with a bespoke tool.

Bug: v8:7786
Bug: v8:7754
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Ia44fd2a66652253f780e3674bf7fb431caef0493
Reviewed-on: https://chromium-review.googlesource.com/1136305
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54526}

For a script '()=>42', the anonymous arrow function has both start and
end position the same as the script function itself. This causes issues
when sorting the SourcePositionEvents of the function, in two ways:

  * If the start positions are the same, we should order by *furthest*
    end position to ensure the stack is in the right order
  * If both start and end are the same, we need to order by function
    literal id to make sure that start order and end order are inversed.

Also, MapLiterals assumes that start+end position uniquely identifies a
function, which is false in this case, so we process the top-level
script function separately in MapLiterals.

Change-Id: I2b2185dc2825018b7ea44c7d0918238e9b1dd972
Reviewed-on: https://chromium-review.googlesource.com/1141741
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54525}

This reverts commit 7f67cbd4.

Reason for revert: Speculative revert because of https://ci.chromium.org/p/v8/builders/luci.v8.ci/Mac%20V8%20FYI%20Release%20(Intel)/1842

Original change's description:
> [turbofan] More brokerization in JSCreateLowering.
> 
> Brokerized ReduceJSCreateEmptyLiteralObject and added the scope
> for ReduceJSCreateLiteralArrayOrObject.
> 
> Bug: v8:7790
> Change-Id: Ife34a6b610678a3fe24152151cf343400ee515bd
> Reviewed-on: https://chromium-review.googlesource.com/1140306
> Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54507}

TBR=jarin@chromium.org,neis@chromium.org,mslekova@chromium.org

Change-Id: Ic4a89cd872b13e4b5f28636e0d91b3b013d6649a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7790
Reviewed-on: https://chromium-review.googlesource.com/1141964Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54524}

R=jgruber@chromium.org

Change-Id: If88adfb7cb9a30a50448a39c71bd899484d29510
Reviewed-on: https://chromium-review.googlesource.com/1139060
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54523}

This CL moves Array.p.fill from JavaScript to a C++ builtin. It has
a generic slow-path and fast-paths implemented via ElementsAccessor in
elements.cc.

R=cbruni@chromium.org

Bug: v8:7624
Change-Id: I8820e1195d2cd9b41c254058923ad9875aab067c
Reviewed-on: https://chromium-review.googlesource.com/1131130
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54522}

This is no longer necessary since we removed the debug context.

R=jgruber@chromium.org

Bug: v8:5530
Change-Id: Ibb9df3a1f139ee076296faedb80204e7fcc23197
Reviewed-on: https://chromium-review.googlesource.com/1134746Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54521}

Spec: http://tc39.github.io/proposal-intl-relative-time/

Design Doc: go/add-intl.relativetimeformat-to-v8

Test: test262/intl402/RelativeTimeFormat/*, intl/relative-time-format/*

R=cira@chromium.org, gsathya@chromium.org

Bug: v8:7869
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Ied95d601cf707db5d555f9d963b9b1f206e37331
Reviewed-on: https://chromium-review.googlesource.com/1124728Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54520}

Bug: v8:7684
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I8ee5aa4a2f481bbe4e47ab3889a9a6084b6b2943
Reviewed-on: https://chromium-review.googlesource.com/1137927Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54519}

R=clemensh@chromium.org

Change-Id: I4f1bda6f0ad420776eb181563d5efbc0d06a911e
Reviewed-on: https://chromium-review.googlesource.com/1141582Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54518}

This reverts commit 1e1cca61.

Reason for revert: breaks builders

Original change's description:
> [tools] Keep raw data in the generated JSON for debugging purposes
> 
> R=​machenbach@chromium.org
> 
> Bug: chromium:861668
> Change-Id: Ic3225ed5919c21a7f6a9f21cba4aa491e1d6606d
> Reviewed-on: https://chromium-review.googlesource.com/1140331
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54508}

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

Change-Id: I10dff94c9cfe08c4a6b6d4d225b429fe16b95d19
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:861668
Reviewed-on: https://chromium-review.googlesource.com/1141784Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54517}

Bug: v8:7790
Change-Id: I12c159ade57a0974c6adc5b277a0b5fd74fd4dfb
Reviewed-on: https://chromium-review.googlesource.com/1140313
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54516}

This helps debugging unexpected traps, as you can figure out which
instruction triggered the trap.

R=mstarzinger@chromium.org

Change-Id: I61735f14e2838ace195f6b84b555b9ddfc06aa0f
Reviewed-on: https://chromium-review.googlesource.com/1140296Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54515}

Convert all remaining uses (in api.cc) to use private local
implementations. These local uses all appear inside deprecated
functions.

Bug: v8:7786
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I86bcafd4c8a737da32fcb8ab275ec708632f9e39
Reviewed-on: https://chromium-review.googlesource.com/1140319
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54514}

Strictly speaking there are some left in api.cc, but they are in
deprecated functions with non-deprecated alternatives.

Apart from changes made using tooling, this also modifies
FieldType::AsClass to return Map* rather than Handle<Map> and converts
its call sites to create the Handle when they need it - currently
several sites immediately dereference the Handle.

Also marks WasmDebugInfo as NeverReadOnlySpaceObject so GetIsolate and
GetHeap remain usable.

Bug: v8:7786
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I7ea5048f97f140c757f651712b8c33a5c7e0ebc1
Reviewed-on: https://chromium-review.googlesource.com/1140302Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54513}

This removes two pointers to Histograms from the memory tracker. These
histograms are stored as part of the Isolate and their lifetime is also
coupled to the Isolate. We cannot bind the pointers but need to pass
them (or the Isolate) as a parameter instead.

R=clemensh@chromium.org
BUG=v8:7424

Change-Id: I6b141b924bd858234641d6603a25fcb08cdf40e3
Reviewed-on: https://chromium-review.googlesource.com/1140312
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54512}

Now we can finally get rid of Map::weak_cell_cache!

BUG=v8:7308

Change-Id: I87a06509bf638bf6833ea2ba1eca525fb4b15df1
Reviewed-on: https://chromium-review.googlesource.com/1128882
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54511}

The BodyDescriptor of an object should use its aligned size.

Change-Id: If743ca130b3cb97c4f25054db6dc887d88fc5e32
Reviewed-on: https://chromium-review.googlesource.com/1140309Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54510}

BUG=v8:7754,v8:5402

Change-Id: Ib3f3a879e68d96cd5d82b1ee461b57dc7367ebe2
Reviewed-on: https://chromium-review.googlesource.com/1139059Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54509}

R=machenbach@chromium.org

Bug: chromium:861668
Change-Id: Ic3225ed5919c21a7f6a9f21cba4aa491e1d6606d
Reviewed-on: https://chromium-review.googlesource.com/1140331Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54508}

Brokerized ReduceJSCreateEmptyLiteralObject and added the scope
for ReduceJSCreateLiteralArrayOrObject.

Bug: v8:7790
Change-Id: Ife34a6b610678a3fe24152151cf343400ee515bd
Reviewed-on: https://chromium-review.googlesource.com/1140306
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54507}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/7315579..e4fb293

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/fb73403..302bb84

Rolling v8/third_party/fuchsia-sdk: https://chromium.googlesource.com/chromium/src/third_party/fuchsia-sdk/+log/8227701..976ce5e

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/c0b1d89..5d1ce93

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

Change-Id: I202ee90eb4c3ea68e2677227dd0ad05cac352be2
Reviewed-on: https://chromium-review.googlesource.com/1141428Reviewed-by: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#54506}

We try to prevent side effects by forbidding running any JavaScript
when we get property from node object.
In case of object node it is possible that by calling property we force
internal object initialization which may force creation of new context,
this initialization can not be made with forbided JavaScript and at the
same time is side effect free.
As workaround we can warmup dom objects first and then generate
description.

R=dgozman@chromium.org

Bug: chromium:827585
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ifd2c6317ffd5cb3822d2a2eedf3d0b0f36a201f1
Reviewed-on: https://chromium-review.googlesource.com/1041078Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54505}

Fixes intl402/Locale/constructor-options-{casefirst,hourcycle,numeric}-invalid

Bug: v8:7684
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I43317f4bb1bb8422940faab1e5afa4162ed9ea11
Reviewed-on: https://chromium-review.googlesource.com/1137476Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54504}

https://chromium.googlesource.com/deps/inspector_protocol/+/0d4255502019144a5dec5669d7992165ae8924e7

Change-Id: I3711883a4cff11f71cca10054e4aac11293f5293
Reviewed-on: https://chromium-review.googlesource.com/1139095Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54503}

This patch makes `d8` recognize files with the `.mjs` extension as
modules instead of classic scripts. This change can be tested by saving
the following JavaScript program as both `module.mjs` and as
`script.js`:

    console.log(this === undefined ? 'strict' : 'sloppy');

Then, run these files in `d8` without passing the `--module` flag:

    $ d8 module.mjs
    strict

    $ d8 script.js
    sloppy

The use of `.mjs` matches not just Google’s recommendation [1] but also
the current modules implementation in Node.js [2].

[1] https://developers.google.com/web/fundamentals/primers/modules
[2] https://nodejs.org/api/esm.html

Bug: v8:7950
Change-Id: I8f39420dc24a5eedd7e88d3b1aa48207ebfeff6e
Reviewed-on: https://chromium-review.googlesource.com/1140314
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54502}

Struct are bundles of value types. They are essentially just shorthand
for passing around a group of individually defined values.

Struct types are declared like this:

  struct A {
    x: Smi;
    y: int32;
  }

and can be constructed explicitly like this:

  A{0, 0}

Structs can be used wherever other types are used (e.g. variables,
parameters, return values) except for parameter/return types of
builtins and runtime functions.

Struct use field access notation to set/get their values like this:

  let a: A = A{0, 0};
  let b: Smi = a.x;
  a.y = 0;

Change-Id: I9fd36a6514c37882831256a49a50809c5db75b56
Reviewed-on: https://chromium-review.googlesource.com/1122133
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54501}

i32 stack parameters can be loaded by Turbofan as 64-bit value, hence
they would not be zero extended. If this loaded value is then passed to
Liftoff (which assumes zero-extended i32 values), we could use it for
memory accesses, which would be out of bounds.

R=mstarzinger@chromium.org

Bug: chromium:864509, v8:6600
Change-Id: I0f45a269b1fb1c2befc2e6bc660c559a88323767
Reviewed-on: https://chromium-review.googlesource.com/1140168
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54500}

Bug: v8:5751


Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: If71ab553f7f70dd148fb90a18ccd9b1c69791323
Reviewed-on: https://chromium-review.googlesource.com/1119103Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Brian Stell <bstell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54499}