Provide a global memory controller used to compute limits for combined
on-heap and embedder memory. The global controller uses the same
mechanism (gc speed, mutator speed) and growing factors as the regular
on-heap controller.

Rely on V8's mechanisms for configured state that stops shrinking the
limit.

Reland:
- API fixes with overrides and default versions.
- Fix of depending on uninitialized values when using the old API.
- GCTracer: Fixed issue in speed computation.
- GCTracer: Added unittests.

This reverts commit 5e043f27.

Bug: chromium:948807
Change-Id: I0f81253b3e1a8b49a7ac107c012a15e33cb514d7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622852Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61735}

Add an {ObjectRef} class to Handle which is returned by {operator->}.
Before, it returned {T} directly, and then used {T::operator->} for
the chained {operator->}.
As a drive-by, this CL also removes {HandleBase::operator*} and
implements this in {Handle<T>} directly.

R=jkummerow@chromium.org

Bug: v8:9183, v8:3770
Change-Id: I0a79fbbc393539543a62773c98a39c7bc2a84b77
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624206Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61734}

Also, when --trace-heap-broker-verbose is on, we trace
bytecode-by-bytecode alterations to the environment.

Change-Id: I535a063cefd57f055711fdd7d7473cb63c963c7f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622851Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61733}

This CL adjusts the tracing to print addresses of interesting
SharedFunctionInfos instead of dereferencing the handles to look
at the name.

Bug: v8:7790
Change-Id: I25d6f96728bd78d8a8becac6f2212f4f7a030c5c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622969Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61732}

R=mstarzinger@chromium.org

Bug: v8:9247
Change-Id: I6819489dd8ed6d5a6f8e2631a5901c7d4b460960
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621943
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61731}

Bug: chromium:965513
Change-Id: I18ff91c98ad6106c5d4df260e6ead6a9e2425dbb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622119
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61730}

KeyedAccessStoreMode is used when creating store handlers to determine
which cases to handle (ex: handle cow, grow) and hence choose an
approriate builtin. It is also used to specify elements kind transitions
which is used when computing ic transitions. The store mode and the
transition mode are independent of each other and it would be cleaner to
use different enums to represent them. This also reduces the total number
of cases in each enum.

Change-Id: I96aeff7a765b312b8088e831776743c67c533bd9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619751Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61729}

NOTRY=true

Bug: v8:9276
Change-Id: Ifd0ec8d86d880ce29101260833528e1aa230de01
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624205Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61728}

..without relying on macros directly inside the class.

Change-Id: If06934e3b54cdd65b393c23ec6bf62af2fd39dfa
Bug: v8:7793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1615256
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61727}

This is a border case that appeared in one of our tests. It seems a good
idea to test for it. It does not seem to be common enough to handle it
specifically (i.e replacing the Word64Equal with a true bool constant)

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:8977, v8:7703
Change-Id: I27e85a2493ab03b92591e788a185d6109904eef1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613252Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61726}

Bug: v8:9247
Change-Id: I79e0553e8a0d6dac2aa16b94a6c0e05b6ccde4a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621934
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61725}

NOTRY=true

Bug: v8:9277
Change-Id: If385439e2bdd8146fe3ba5734920b2096b6c1789
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622853Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61724}

The HandleApiCall uses BUILTIN_EXIT frames now instead of EXIT frames,
so API calls show up in stack traces. We no longer need API builtins
and this CL removes them and the corresponding C++ macros.

Bug: v8:9183
Change-Id: Ifa2e842123ef7e96b2ff296116f46d5d799a63ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617249
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61723}

This is mainly a torque change, but as a drive-by we get rid of
kStartOfPointerFieldsOffset
kEndOfTaggedFieldsOffset
which often are used to enclose a section of pointers in an object.

Bug: v8:7793
Change-Id: I52d83d09249a3cc6a99e7e7506e154ccfca53a12
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1615249
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61722}

TBR=mythria@chromium.org
NOTRY=true

Bug: v8:9246
Change-Id: I18d6c22da5746d3af34c65ea22fd5ef80e4f13fb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622850Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61721}

New revision: fe0467fd105a9ea90fbb091dc2a7b4cdbf539803

Change-Id: I0c53935b719194f16ade131f703d656749ace3d3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1623586Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Alexei Filippov <alph@chromium.org>
Auto-Submit: Andrey Lushnikov <lushnikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61720}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/12e7bf6..0742a14

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/5655d8f..535dc1d

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/5716400..c7e440c

Rolling v8/third_party/googletest/src: https://chromium.googlesource.com/external/github.com/google/googletest/+log/9d4cde4..f71fb4f

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/5b1310e..2db48c7

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

Change-Id: Icfaca034cd7956805b8ba7815c97bc4ba219ca3a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1623633Reviewed-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@{#61719}

At the moment the implementation of LoadElemSegmentImpl is not ready
to support the loading of passive element segments into tables with
index > 0. I added a check so that we notice when somebody starts to
implement it.

R=binji@chromium.org

Bug: v8:9270
Change-Id: I118da434cc379bbdb7bcef4af847216f5124551f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622105Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61718}

Now that we support a max_samples parameter, it isn't actually necessary
to have a record_samples flag (as it can just be modeled by 0).

Change-Id: I578ecc9f6ee73ecbe1f93d0d04ee8028a9a2716d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611015
Commit-Queue: Andrew Comminos <acomminos@fb.com>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61717}

This reverts commit dac86be2.

Reason for revert: Still failing msan: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/26904

Original change's description:
> Reland "[heap] Add global memory controller"
> 
> Provide a global memory controller used to compute limits for combined
> on-heap and embedder memory. The global controller uses the same
> mechanism (gc speed, mutator speed) and growing factors as the regular
> on-heap controller.
> 
> Rely on V8's mechanisms for configured state that stops shrinking the
> limit.
> 
> This reverts commit 5e043f27.
> 
> Tbr: ulan@chromium.org
> Bug: chromium:948807
> Change-Id: Id4f94e7dcb458d1d0d2f872194f8f3ea0959a73f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622968
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61715}

TBR=ulan@chromium.org,mlippautz@chromium.org

Change-Id: If30649f158a08fd185f2771a13b8e09cf53fb667
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:948807
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622849Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61716}

Provide a global memory controller used to compute limits for combined
on-heap and embedder memory. The global controller uses the same
mechanism (gc speed, mutator speed) and growing factors as the regular
on-heap controller.

Rely on V8's mechanisms for configured state that stops shrinking the
limit.

This reverts commit 5e043f27.

Tbr: ulan@chromium.org
Bug: chromium:948807
Change-Id: Id4f94e7dcb458d1d0d2f872194f8f3ea0959a73f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622968Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61715}

This is a reland of 748de1e5

Original change's description:
> [fuchsia] Replace zx_clock_get() with zx_clock_get_new().
>
> zx_clock_get() signature is being replaced to report errors.
> As part of a soft transition, zx_clock_get_new() is introduced with
> the final function signature.
>
> Bug: chromium:963956
> Change-Id: Ia6d0f4fc560bd9149683011099b064540b54edd6
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1616545
> Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
> Reviewed-by: Wez <wez@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61591}

Bug: chromium:963956
Change-Id: I555df23d448fa246e4edec36b349a3c0aaad66ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617805
Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61714}

This reverts commit cfe281f3.

Reason for revert: Fails on gcc bots

Original change's description:
> [heap] Add global memory controller
> 
> Provide a global memory controller used to compute limits for combined
> on-heap and embedder memory. The global controller uses the same
> mechanism (gc speed, mutator speed) and growing factors as the regular
> on-heap controller.
> 
> Rely on V8's mechanisms for configured state that stops shrinking the
> limit.
> 
> Bug: chromium:948807
> Change-Id: I3283a2c28e6ab889f8d2ad85c9b67b8f234b9900
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619762
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61712}

TBR=ulan@chromium.org,hpayer@chromium.org,mlippautz@chromium.org,bikineev@chromium.org

Change-Id: I503d5a1436eb9156556b5bca852d2b2f9da2446f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:948807
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622967Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61713}

Provide a global memory controller used to compute limits for combined
on-heap and embedder memory. The global controller uses the same
mechanism (gc speed, mutator speed) and growing factors as the regular
on-heap controller.

Rely on V8's mechanisms for configured state that stops shrinking the
limit.

Bug: chromium:948807
Change-Id: I3283a2c28e6ab889f8d2ad85c9b67b8f234b9900
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619762
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61712}

These instructions were renamed in the October 2, WebAssembly CG meeting. The
issue describing the change is here:

https://github.com/WebAssembly/spec/issues/884

Change-Id: Ia9e8733156b5ed5db7fc9ab1681c1a51b874dd71
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1620681Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ben Smith <binji@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61711}

This method is rarely used, and has several problems:
1) It CHECKs that the value is not undefined, then creates a
   {Handle<T>} which again DCHECKs that the value is of type {T}.
2) It is called on a raw {FixedArray} but returns a handle.
3) It is often used when no handle is actually needed, adding
   unnecessary overhead.
4) It adds complexity and hides actual checks and handlification.

This CL removes that method, replacing some uses by explicit CHECKs (in
tests) and relying on the DCHECKs in the casts otherwise.

R=mstarzinger@chromium.org

Bug: v8:9183
Change-Id: I90ff59e8b78c909a9a207029d8cc9ab16c0c7b56
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621939
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61710}

Design Doc: https://goo.gl/ZAtL1f

Bug: v8:8515
Change-Id: I543ab704fd3f8b41e396879ebbc581977ec0ff10
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1612325Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61709}

HeapObjectIterator now has a DCHECK preventing iterating over read-only
space. This removes DumpMaps and switches to ReadOnlyHeapIterator
instead.

Bug: v8:7464
Change-Id: Ifd186d0e26d94c315308aa3a6ecb9da02a270fc1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622120
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61708}

Bug: v8:9264
Change-Id: I936d203d38410a6aefff8a54acf49468abb20e39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621933
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61707}

StringPrototypeCharAt, StringPrototypeCharCodeAt, StringPrototypeCodePointAt

Bug: v8:8996
Change-Id: I7faaec880801cfe244654a257dc98f67d4bc39ea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617807Reviewed-by: Simon Zünd <szuend@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#61706}

This makes the API more consistent.

Originally I planned to use this to template iterators inside mkgrokdump, but
I decided against it.

Bug: v8:9183
Change-Id: Iefa372370a7cc7c637dc86c0bfb837a91a2bc6e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622116Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Cr-Commit-Position: refs/heads/master@{#61705}

R=tebbi@chromium.org

Change-Id: I3f34eeaf4ab9a198ffc68a8c974f0bf35a0582e9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622117
Commit-Queue: Georg Schmid <gsps@google.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61704}

This was already unsupported by the map updated because the condition was
manually checked before CanBeInPlaceChangedTo. Since the latter function missed
the check, however, new code using the function (json parser) missed the
relevant check. Simply move the condition to the function.

Bug: chromium:964869
Change-Id: I9424a5706c5f6d637acbf532707da3f1e7d9b55e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622114
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61703}

R=yangguo@chromium.org

Change-Id: Ic688665dc137bb0a1c0875f76b1c2b6360a10e2b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1615243
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61702}

When tracing function compilations, do also trace the function index
and the function body size. This information often helps investigating
bottlenecks in compilation.

R=ahaas@chromium.org

Bug: v8:8916, chromium:950493
Change-Id: Ibabd1b59827b67ac9b0ef3a78f121ab8fb2c4e09
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622111Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61701}

Check uintptr_t sized blocks of UTF16 chars at a time similar to NonAsciiStart.

Fix readds the length precheck so we won't read out of bounds while aligning
the start.

Change-Id: Iaea901945a2445ba5bf50c67a6211356697ed1fd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622115
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61700}

Change-Id: Ifd8734aa682e238de54284c74209d236c7ac824f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622110Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61699}

Bug: v8:9183
Change-Id: Ibdf4633a9a57d0a37e1e2ef8930471e6acbf7e13
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621944Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Cr-Commit-Position: refs/heads/master@{#61698}

This reverts commit c2e4183a.

Reason for revert: Uninitialized value on MSAN, see https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/26888

Original change's description:
> [runtime] Speed up String::IsOneByte
> 
> Check uintptr_t sized blocks of UTF16 chars at a time similar to NonAsciiStart.
> 
> Change-Id: Ib4c498cc064e6ac7b6f8cc87ab700eafc8132c39
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622107
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61693}

TBR=ishell@chromium.org,verwaest@chromium.org

Change-Id: I2e18c9476f0ed47e77da87d2308a3429ef4f515c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622112Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61697}

This CL changes the existing TorqueError struct into a more general
TorqueMessage by adding a "kind" enum. The contextual for lint errors
is removed and replaced by a list of TorqueMessages.

A MessageBuilder is introduced to help with the different
combinations of present information and method of reporting. A lint
error with custom SourcePosition can be reported like this:

Lint("naming convention error").Position(<src_pos_var>);

While a fatal error, with CurrentSourcePosition can be thrown
like this:

Error("something went horrible wrong").Throw();

This approach is both backwards compatible and should prove flexible
enough to add more information to messages or add other message kinds.

Bug: v8:7793
Change-Id: Ib04fa188e34b3e8e9a6526a086f80da8f690a6f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617245
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61696}