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 is a reland of c48096d442
Original change's description:
> Reland "[runtime] Remove extension slots from context objects"
>
> This is a reland of c07c02e1c4
>
> 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}
This reverts commit c48096d442.
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 c07c02e1c4
>
> 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/+/1871922
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64424}
This is a reland of c07c02e1c4
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}
This reverts commit c07c02e1c4.
Reason for revert: MSAN failures:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/29251
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=ulan@chromium.org,jgruber@chromium.org,petermarshall@chromium.org,leszeks@chromium.org,verwaest@chromium.org,victorgomes@google.com
Change-Id: I98dee04ab4d3ae977053982ec884b738d2f6f623
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9744
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1868611
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64373}
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}
This is a reland of c7c47c68f2.
This makes TSAN happy in addition to:
Previously I presumed that the context read from a frame in the profiler was
a valid context. Turns out that on non-intel we're not guaranteed that the
frame is properly set up. In the case we looked at, the profiler took a
sample right before writing the frame marker indicating a builtin frame,
causing the "context" pointer from that frame to be a bytecode array. Since
we'll read random garbage on the stack as a possible context pointer, I made
the code reading the native context from it a little more defensive.
Bug: v8:9860
Tbr: ulan@chromium.org, neis@chromium.org, ishell@chromium.org
Original change's description:
> [runtime] Move Context::native_context to the map
>
> Remove the native context slot from contexts by making context maps
> native-context-specific. Now we require 2 loads to go from a context to the
> native context, but we have 1 field fewer to store when creating contexts.
>
> Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64296}
Change-Id: I4d0ab4cbbb23a9ae616407f17ef8f35a0b68ddb4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1864654
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64360}
This reverts commit c7c47c68f2.
Reason for revert: breaks TSAN
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/28738
Original change's description:
> Reland "[runtime] Move Context::native_context to the map"
>
> This is a reland of f05bae1e0d
>
> Previously I presumed that the context read from a frame in the profiler was
> a valid context. Turns out that on non-intel we're not guaranteed that the
> frame is properly set up. In the case we looked at, the profiler took a
> sample right before writing the frame marker indicating a builtin frame,
> causing the "context" pointer from that frame to be a bytecode array. Since
> we'll read random garbage on the stack as a possible context pointer, I made
> the code reading the native context from it a little more defensive.
>
> Bug: v8:9860
>
> Original change's description:
> > [runtime] Move Context::native_context to the map
> >
> > Remove the native context slot from contexts by making context maps
> > native-context-specific. Now we require 2 loads to go from a context to the
> > native context, but we have 1 field fewer to store when creating contexts.
> >
> > Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
> > Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> > Reviewed-by: Igor Sheludko <ishell@chromium.org>
> > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> > Reviewed-by: Maya Lekova <mslekova@chromium.org>
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#64296}
>
> Change-Id: If9461e9b21d35a260d71c79d7f95e518cc429e09
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1864930
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Auto-Submit: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64314}
TBR=ulan@chromium.org,neis@chromium.org,petermarshall@chromium.org,ishell@chromium.org,verwaest@chromium.org,mslekova@chromium.org,victorgomes@google.com
Change-Id: I4f9edc62ea6f9f5857619ff0ad1a63cab4b33cc3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9860
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1864937
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64316}
This is a reland of f05bae1e0d
Previously I presumed that the context read from a frame in the profiler was
a valid context. Turns out that on non-intel we're not guaranteed that the
frame is properly set up. In the case we looked at, the profiler took a
sample right before writing the frame marker indicating a builtin frame,
causing the "context" pointer from that frame to be a bytecode array. Since
we'll read random garbage on the stack as a possible context pointer, I made
the code reading the native context from it a little more defensive.
Bug: v8:9860
Original change's description:
> [runtime] Move Context::native_context to the map
>
> Remove the native context slot from contexts by making context maps
> native-context-specific. Now we require 2 loads to go from a context to the
> native context, but we have 1 field fewer to store when creating contexts.
>
> Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64296}
Change-Id: If9461e9b21d35a260d71c79d7f95e518cc429e09
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1864930
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Auto-Submit: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64314}
This reverts commit f05bae1e0d.
Reason for revert: broke arm sim debug
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/17714https://logs.chromium.org/logs/v8/buildbucket/cr-buildbucket.appspot.com/8899519852984476944/+/steps/Check_-_trusted/0/logs/FunctionDetailsInlining/0
Original change's description:
> [runtime] Move Context::native_context to the map
>
> Remove the native context slot from contexts by making context maps
> native-context-specific. Now we require 2 loads to go from a context to the
> native context, but we have 1 field fewer to store when creating contexts.
>
> Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64296}
TBR=ulan@chromium.org,neis@chromium.org,petermarshall@chromium.org,ishell@chromium.org,verwaest@chromium.org,mslekova@chromium.org,victorgomes@google.com
Change-Id: Ie7b4086c3a9ab2627ecac599da36b20cf8d1f948
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863200
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64299}
Remove the native context slot from contexts by making context maps
native-context-specific. Now we require 2 loads to go from a context to the
native context, but we have 1 field fewer to store when creating contexts.
Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64296}
This patch refactors the declaration and allocation of the class variable, and
implements static private methods:
- The class variable is declared in the class scope with an explicit
reference through class_scope->class_variable(). Anonymous classes
whose class variable may be accessed transitively through static
private method access use the dot string as the class name. Whether
the class variable is allocated depending on whether it is used.
Other references of the class variable in the ClassLiteral AST node
and the ClassInfo structure are removed in favor of the reference
through the class scope.
- Previously the class variable was always (stack- or context-)
allocated if the class is named. Now if the class variable is only
referenced by name, it's stack allocated. If it's used transitively
by access to static private methods, or may be used through eval,
it's context allocated. Therefore we now use 1 less context slots
in the class context if it's a named class without anyone referencing
it by name in inner scopes.
- Explicit access to static private methods or potential access to
static private methods through eval results in forced context
allocation of the class variables. In those cases, we save its index
in context locals in the ScopeInfo and deserialize it later, so that
we can check that the receiver of static private methods is the class
constructor at run time. This flag is recorded as
HasSavedClassVariableIndexField in the scope info.
- Classes that need the class variable to be saved due to
access to static private methods now save a
ShouldSaveClassVariableIndexField in the preparse data so that the
bits on the variables can be updated during a reparse. In the case
of anonymous classes that need the class variables to be saved,
we also re-declare the class variable after the reparse since
the inner functions are skipped and we need to rely on the preparse
data flags to remember declaring it.
Design doc: https://docs.google.com/document/d/1rgGRw5RdzaRrM-GrIMhsn-DLULtADV2dmIdh_iIZxlc/edit
Bug: v8:8330
Change-Id: Idd07803f47614e97ad202de3b7faa9f71105eac5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1781011
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64219}
Victor Gomes
Clemens Backes
Leszek Swirski
Sathya Gunasekaran
Toon Verwaest
Joshua Litt
Joyee Cheung