... mainly by adapting Object::Compare and
CodeStubAssembler::RelationalComparison.
TBR=rmcilroy@chromium.org
Change-Id: I34448d45b4950b9318263c4a667aa9db7d77232d
Bug: v8:6791
Reviewed-on: https://chromium-review.googlesource.com/730730
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48873}
- Introduce the new union type UnionType<T1,T2>, used for Number and
Numeric. Similarly, PairType<T1,T2> is used for a Turbofan operation
with two results. Further details in the design doc:
https://docs.google.com/document/d/10foP3m7SDWyFfbda96iEJ_XYOLQdd32AeoP8SD1cTcs/edit#heading=h.bghdno28mr7u
- Allow to derive the MachineType from a static type.
This allows to select the right MachineType when performing a
load/store.
- Disallow casts (UncheckedCast() or CAST()) when the target and
origin type have no overlap.
New cast ReinterpretCast() is an UncheckedCast without this check.
- Caveat of this CL: Checked casts (CAST()) are not possible for
UnionType<T1,T2> with the exception of Number (due to the existence
of Number in OBJECT_TYPE_LIST and the existence of an IsNumber()
function in the runtime).
Bug: v8:6949
Change-Id: I21a683d1341f69cebd8a347f545b454b463c52ad
Reviewed-on: https://chromium-review.googlesource.com/723320
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48796}
Also ensure that CSA's CloneFixedArray and ExtractFixedArray correctly
transition COW to non-COW maps when doing a clone requiring copying.
Bug: chromium:775888
Change-Id: I31c97072761fdd2360d86f840c9fd6ab2d72973a
Reviewed-on: https://chromium-review.googlesource.com/727900
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48754}
This adds a single bottleneck that properly handles the copying of empty, COW
and FixedDoubleArray arrays under the control of flags. This is in preparation
of adding new CSA-based array builtins on Array.prototype.
Drive by: Fix SmiConstant handling when ENABLE_VERIFY_CSA is not active and
make the use of constant detection/folding consistent in the CSA depending
on ParameterMode.
Change-Id: If1889ab8cbff1805286b7b4344c29ffbe7191b39
Reviewed-on: https://chromium-review.googlesource.com/715798
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48624}
This is a reland of 3d023952f2
Original change's description:
> [runtime] Make JSFunction::prototype_or_initial_map field optional.
>
> Functions that don't have prototype need to store neither prototype nor
> initial map, so the |prototype_or_initial_map| field is not required for
> such maps.
>
> Bug: v8:6459
> Change-Id: I4b3066bd6a4fed42c19f217bae82a8bce552bdca
> Reviewed-on: https://chromium-review.googlesource.com/570250
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46840}
Bug: v8:6459
Change-Id: I54e3516ea70474c6d4f873f7b91e74cb8a7d622a
Reviewed-on: https://chromium-review.googlesource.com/583307
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48523}
These will be used in subsequent CLs to add spec-compliant builtins
on Array.prototype built with the CSA.
Change-Id: I4c9f72f90dffe018b99efdc73e9d40b3d175c2aa
Reviewed-on: https://chromium-review.googlesource.com/704115
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48362}
Change-Id: Ib36b6e27476f7cc1e2064e147fbfa7d3d1e28b49
These will be used in subsequent CLs to add spec-compliant builtins
on Array.prototype built with the CSA.
Change-Id: Ib36b6e27476f7cc1e2064e147fbfa7d3d1e28b49
Reviewed-on: https://chromium-review.googlesource.com/700694
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48306}
TurboAssembler::CallRecordWriteStub contains info that could be used to
conditionally skip generational write barrier or skip saving float-point
registers. This commits uses those info in RecordWrite stub.
Bug: chromium:749486
Change-Id: I41c9a593473e1f8863a09887fd2ce917f1d4fb3b
Reviewed-on: https://chromium-review.googlesource.com/672527
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Albert Mingkun Yang <albertnetymk@google.com>
Cr-Commit-Position: refs/heads/master@{#48123}
Given that the index we use is checked to be in array index range there is no
need for a costly ToString conversion. All involved helpers for lookup up
properties directly support Smi/HeapNumber indices directly.
Cleanup: Rename GotoUnlessNumberLessThan => GotoIfNumberGreaterThanOrEqual
Change-Id: Iaddc4940f5d984572aa218d568ca71bf694cee74
Reviewed-on: https://chromium-review.googlesource.com/640388
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48039}
Given that we no longer need to iterate over lists of optimized JS functions
(c.f. https://chromium-review.googlesource.com/c/v8/v8/+/647596), we can
remove this field. Thus saving the size of one pointer per function.
Bug: v8:6637
Change-Id: If77951f2eddba33ba350fa9ddf03a4edb3f7c7d8
Reviewed-on: https://chromium-review.googlesource.com/652373
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Juliana Patricia Vicente Franco <jupvfranco@google.com>
Cr-Commit-Position: refs/heads/master@{#47875}
Instead of using a word to store the status of the promise, this
patch uses 2 bit on flags.
Bug: v8:5046
Change-Id: Ic651338230dbe1704c68de8652676f236a3298f0
Reviewed-on: https://chromium-review.googlesource.com/634623
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47628}
The new node behave the same as its counterpart, CallCFunction, with the
additional saving and restoring caller saved registers before and after
the function call.
Bug: chromium:749486
Change-Id: I0a1dfb2e4e55f7720541a00e6d16fd20220f39ed
Reviewed-on: https://chromium-review.googlesource.com/620709
Commit-Queue: Albert Mingkun Yang <albertnetymk@google.com>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47479}
Previously TryToName bailed out for Oddball keys (i.e. when passing true
or false as the key), which meant that for example the generic
KeyedLoadIC would always bail out to the %KeyedGetProperty runtime
function. But handling Oddball keys is fairly easy, since every oddball
value carries it's unique string representation. Adding just this case
to the CodeStubAssembler::TryToName method boosts this simple
micro-benchmark by a factor of 4x:
const n = 1e7;
const obj = {};
const key = true;
console.time('foo');
for (let i = 0; i < n; ++i) {
if (obj[key] === undefined) {
obj[key] = key;
}
}
console.timeEnd('foo');
It also shows on the ARES-6 ML benchmark and on several Speedometer
tests, where objects are being used as dictionaries and the developers
rely on the implicit ToString conversions on the property accesses.
In the ARES-6 ML benchmark, the number of calls to %KeyedGetProperty
is reduced by 137,758.
Bug: v8:6278, v8:6344, v8:6670
Change-Id: Iaa965e30be4c247682a67ec09543655df9b761d2
Reviewed-on: https://chromium-review.googlesource.com/599527
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47105}
The @@toStringTag lookup in Object.prototype.toString causes quite a
lot of overhead and oftentimes dominates the builtin performance. These
lookups are almost always negative, especially for primitive values,
and Object.prototype.toString is often used to implement predicates
(like in Node core or in AngularJS), so having a way to skip the
negative lookup yields big performance gains.
This CL introduces a "MayHaveInterestingSymbols" bit on every map,
which says whether instances with this map may have an interesting
symbol. Currently only @@toStringTag is considered an interesting
symbol, but we can extend that in the future.
In the Object.prototype.toString we can use the interesting symbols
bit to do a quick check on the prototype chain to see if there are
any maps that might have the @@toStringTag, and if not, we can just
immediately return the result, which is very fast because it's derived
from the instance type. This also avoids the ToObject conversions for
primitive values, which is important, since this causes unnecessary
GC traffic and in for example AngularJS, strings are also often probed
via the Object.prototype.toString based predicates.
This boosts Speedometer/AngularJS by over 3% and Speedometer overall
by up to 1%. On the microbenchmark from the similar SpiderMonkey bug
(https://bugzilla.mozilla.org/show_bug.cgi?id=1369042), we go from
roughly 450ms to 70ms, which corresponds to a 6.5x improvement.
```
function f() {
var res = "";
var a = [1, 2, 3];
var toString = Object.prototype.toString;
var t = new Date;
for (var i = 0; i < 5000000; i++)
res = toString.call(a);
print(new Date - t);
return res;
}
f();
```
The design document at https://goo.gl/e8CruQ has some additional
data points.
TBR=ulan@chromium.org
Bug: v8:6654
Change-Id: I31932cf41ecddad079d294e2c322a852af0ed244
Reviewed-on: https://chromium-review.googlesource.com/593620
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47034}
Empty Array literals are amongst the most commonly used literal types on our
top25 page list. Using a custom bytecode we can drop the boilerplate for empty
Array literals alltogether. However, we still need a proper AllocationSite to
track ElementsKind transitions.
Bug: v8:6211, chromium:746935
Change-Id: I891eaa778e4e81e138e483a65f04ae00ae30bd28
Reviewed-on: https://chromium-review.googlesource.com/580932
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46875}
This reverts commit 3d023952f2.
Reason for revert: breaks gcc build
Original change's description:
> [runtime] Make JSFunction::prototype_or_initial_map field optional.
>
> Functions that don't have prototype need to store neither prototype nor
> initial map, so the |prototype_or_initial_map| field is not required for
> such maps.
>
> Bug: v8:6459
> Change-Id: I4b3066bd6a4fed42c19f217bae82a8bce552bdca
> Reviewed-on: https://chromium-review.googlesource.com/570250
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46840}
TBR=jkummerow@chromium.org,jarin@chromium.org,ishell@chromium.org
Change-Id: Ie9951c87b15c8bd365ed187d7f719b8f08dd0bb5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6459
Reviewed-on: https://chromium-review.googlesource.com/583088
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46841}
Functions that don't have prototype need to store neither prototype nor
initial map, so the |prototype_or_initial_map| field is not required for
such maps.
Bug: v8:6459
Change-Id: I4b3066bd6a4fed42c19f217bae82a8bce552bdca
Reviewed-on: https://chromium-review.googlesource.com/570250
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46840}
This reverts commit 4851745fe3.
Reason for revert: Top crasher on Canary, see https://crbug.com/746935
Original change's description:
> [literals] Introduce CreateEmptyArrayLiteral Bytecode
>
> Empty Array literals are amongst the most commonly used literal types on our
> top25 page list. Using a custom bytecode we can drop the boilerplate for empty
> Array literals alltogether. However, we still need a proper AllocationSite to
> track ElementsKind transitions.
>
> Bug: v8:6211
> Change-Id: Id5dbdac0ea8e24dd474e679c902c6e4a2957af1d
> Reviewed-on: https://chromium-review.googlesource.com/567079
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46752}
TBR=rmcilroy@chromium.org,mstarzinger@chromium.org,cbruni@chromium.org,ishell@chromium.org,rmcilroy@google.com
Bug: v8:6211, chromium:746935
Change-Id: Ibf19a923688c071d03bad8661a10e08f8414db56
Reviewed-on: https://chromium-review.googlesource.com/580193
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46804}
Empty Array literals are amongst the most commonly used literal types on our
top25 page list. Using a custom bytecode we can drop the boilerplate for empty
Array literals alltogether. However, we still need a proper AllocationSite to
track ElementsKind transitions.
Bug: v8:6211
Change-Id: Id5dbdac0ea8e24dd474e679c902c6e4a2957af1d
Reviewed-on: https://chromium-review.googlesource.com/567079
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46752}
Add SetProperties as the generic interface to set properties. In the
future, this will switch based on the input properties type and
correctly store the hash code.
This patch also updates tests to check against empty_property_array
instead of empty_fixed_array.
Bug: v8:6404
Change-Id: I39d324ea3ab3cc2c2223b6f4be64139bb88edd94
Reviewed-on: https://chromium-review.googlesource.com/574761
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46744}
- use asm_tester instead of data variable name
- directly expose Variable and Label for convenience
Change-Id: I211fe07e236f96067037ca00c1435c1491121e6b
Reviewed-on: https://chromium-review.googlesource.com/574914
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46738}
This patch changes the backing store of slow properties to be a
new instance type called PropertyArray.
Currently the only difference between this and a FixedArray is
the map. A future patch will change the length property to store
the hash code.
Bug: v8:5717, v8:6404
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Iaebc98f42e6d93c1392772e6f837787beb64afec
Reviewed-on: https://chromium-review.googlesource.com/539028
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46569}
This adds a convenience method for the common Smi to int conversion
pattern.
Bug:
Change-Id: I7d7b171c36cfec5f6d10c60f1d9c3e06e3aed0fa
Reviewed-on: https://chromium-review.googlesource.com/563205
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Andreas Rossberg <rossberg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46516}
The `FAST_` prefix doesn’t make much sense — they’re all just different cases
with their own optimizations. Packedness being implicit (e.g. `FAST_ELEMENTS`
vs. `FAST_HOLEY_ELEMENTS`) is not ideal, either.
This patch renames the FAST elements kinds as follows:
- e.g. FAST_ELEMENTS => PACKED_ELEMENTS
- e.g. FAST_HOLEY_ELEMENTS => HOLEY_ELEMENTS
The following exceptions are left intact, for lack of a better name:
- FAST_SLOPPY_ARGUMENTS_ELEMENTS
- SLOW_SLOPPY_ARGUMENTS_ELEMENTS
- FAST_STRING_WRAPPER_ELEMENTS
- SLOW_STRING_WRAPPER_ELEMENTS
This makes it easier to reason about elements kinds, and less confusing to
explain how they’re used.
R=jkummerow@chromium.org, cbruni@chromium.org
BUG=v8:6548
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ie7c6bee85583c3d84b730f7aebbd70c1efa38af9
Reviewed-on: https://chromium-review.googlesource.com/556032
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46361}
This CL enforces passing an AssemblerDebugInfo object to Bind, most convently
acheived by the BIND macro.
Change-Id: I092714f10803f529d01d2fe716b96275b2bee806
Reviewed-on: https://chromium-review.googlesource.com/508729
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45433}
Consistently support calls to host-C-linkage functions with up to 9 arguments
from the simulator, and check that these limits aren't exceeded accidentally.
BUG=v8:6281
Review-Url: https://codereview.chromium.org/2825393003
Cr-Commit-Position: refs/heads/master@{#44790}
The spec requires truncation while ToUint32 originally rounded down.
This also adds a bunch of test cases to check edge case behavior.
BUG=v8:6212
Review-Url: https://codereview.chromium.org/2805783003
Cr-Commit-Position: refs/heads/master@{#44487}
Cleanup CHECK_EQ order and simplify CHECK_EQ(true/false).
Cleanup callorder for negative numbers
Cleanup callorder order for capital letter constants.
Cleanup callorder for test.x checks.
BUG=
Review-Url: https://codereview.chromium.org/2677183002
Cr-Commit-Position: refs/heads/master@{#42997}
TypeFeedbackVectors are strongly rooted by a closure. However, in modern
JavaScript closures are created and abandoned more freely. An important
closure may not be present in the root-set at time of garbage collection,
even though we've cached optimized code and use it regularly. For
example, consider leaf functions in an event dispatching system. They may
well be "hot," but tragically non-present when we collect the heap.
Until now, we've relied on a weak root to cache the feedback vector in
this case. Since there is no way to signal intent or relative importance,
this weak root is as susceptible to clearing as any other weak root at
garbage collection time.
Meanwhile, the feedback vector has become more important. All of our
ICs store their data there. Literal and regex boilerplates are stored there.
If we lose the vector, then we not only lose optimized code built from
it, we also lose the very feedback which allowed us to create that optimized
code. Therefore it's vital to express that dependency through the root
set.
This CL does this by creating a strong link to a feedback
vector at the instantiation site of the function closure.
This instantiation site is in the code and feedback vector
of the outer closure.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2674593003
Cr-Commit-Position: refs/heads/master@{#42953}
They have the same lifetime. It's a match!
Both structures are native context dependent and dealt with (creation,
clearing, gathering feedback) at the same time. By treating the spaces used
for literal boilerplates as feedback vector slots, we no longer have to keep
track of the materialized literal count elsewhere.
A follow-on CL removes even more parser infrastructure related to this count.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2655853010
Cr-Commit-Position: refs/heads/master@{#42771}
- kDebugPromiseCreated(task, parent_task)
This event occurs when promise is created (PromiseHookType::Init). V8Debugger uses this event to maintain task -> parent task map.
- kDebugEnqueueAsyncFunction(task)
This event occurs when first internal promise for async function is created. V8Debugger collects stack trace at this point.
- kDebugEnqueuePromiseResolve(task),
This event occurs when Promise fulfills with resolved status. V8Debugger collects stack trace at this point.
- kDebugEnqueuePromiseReject(task),
This event occurs when Promise fulfills with rejected status. V8Debugger collects stack trace at this point.
- kDebugPromiseCollected,
This event occurs when Promise is collected and no other chained callbacks can be added. V8Debugger removes information about async task for this promise.
- kDebugWillHandle,
This event occurs when chained promise function (either resolve or reject handler) is called. V8Debugger installs parent promise's stack (based on task -> parent_task map) as current if available or current promise's scheduled stack otherwise.
- kDebugDidHandle,
This event occurs after chained promise function has finished. V8Debugger restores asynchronous call chain to previous one.
With this change all instrumentation calls are related to current promise (before WillHandle and DidHandle were related to next async task).
Before V8Debugger supported only the following:
- asyncTaskScheduled(task1)
- asyncTaskStarted(task1)
- asyncTaskFinished(task1)
Now V8Debugger supports the following:
- asyncTaskScheduled(parent_task)
..
- asyncTaskCreated(task, parent_task),
- asyncTaskStarted(task), uses parent_task scheduled stack
- asyncTaskScheduled(task)
- asyncTaskFinished(task)
Additionally: WillHandle and DidHandle were migrated to PromiseHook API.
More details: https://docs.google.com/document/d/1u19N45f1gSF7M39mGsycJEK3IPyJgIXCBnWyiPeuJFE
BUG=v8:5738
R=dgozman@chromium.org,gsathya@chromium.org,yangguo@chromium.org
Review-Url: https://codereview.chromium.org/2650803003
Cr-Commit-Position: refs/heads/master@{#42644}
