Change-Id: I69a4db1d8be47bad56df74447a29526e9623cb80
Reviewed-on: https://chromium-review.googlesource.com/1243107
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56219}

I moved AnalyzePartially from ParseFunctionLiteral to SkipFunction, but arrow
functions only used the ResetAfterPreparsing part.

Bug: chromium:888825

Change-Id: I08de99af128b28031df6ed86a725e4dc918078f8
Reviewed-on: https://chromium-review.googlesource.com/1243383Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56218}

We already had checksumming for code cache data. We now extend
checksumming to the startup snapshot to catch data corruption early.

The performance impact for deserialization is a regression of 1-2%,
which should be acceptable.

Sample output for the included test with --profile-deserialization:

[Verifying snapshot checksum took 0.023 ms]
[Deserializing isolate (134348 bytes) took 1.891 ms]
[Verifying snapshot checksum took 0.024 ms]
[Deserializing isolate (134348 bytes) took 1.654 ms]
[Deserializing context #0 (47208 bytes) took 0.331 ms]
Deserialization will reserve:
    208168 bytes per isolate
    123368 bytes per context #0
Snapshot blob consists of:
    134492 bytes in 6 chunks for startup
    115272 bytes for builtins
     47152 bytes in 31 chunks for context #0
[Verifying snapshot checksum took 0.048 ms]
[Verifying snapshot checksum took 0.043 ms]

R=peria@chromium.org, petermarshall@chromium.org

Bug: chromium:881417
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: Ibc57520d459c86be8972f731aa35045b5e3751d7
Reviewed-on: https://chromium-review.googlesource.com/1241874Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56217}

.. otherwise V8 crashes on attempt to use imported function as part
of expression passed to Debugger.evaluateOnCallFrame.

R=neis@chromium.org

Bug: chromium:878029
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I61b837f5c7b84a80d91a9cdaaac0422a24aa1620
Reviewed-on: https://chromium-review.googlesource.com/1241475Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56216}

This reduces the size a "Throw" or "Rethrow" takes in generated code by
switching from runtime calls to using WebAssembly runtime stubs. It also
removes a specialized runtime function and instead uses {Runtime_Throw}
which is generic and used by all code (including JavaScript code).

R=clemensh@chromium.org
BUG=v8:8091

Change-Id: Id4f637525f2ea9d81227931b1290d90ca5f376d1
Reviewed-on: https://chromium-review.googlesource.com/1243106
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56215}

Whenever we insert new code in the module, we call {set_code} and
{PatchJumpTable}. This CL refactors these two calls into a new
{InstallCode} method. This method will be extended in a future CL to
maintain a counter of potentially dead code and trigger GC.

R=mstarzinger@chromium.org

Bug: v8:8217
Change-Id: I1a1421806c8518cf7b6b78fe4aa2e969d4e4dde6
Reviewed-on: https://chromium-review.googlesource.com/1243003
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56214}

The lifetime of the AsyncCompileJob does not depend on the lifetime of
the stream which feeds data into it. Multiple checks guarantee that the
AsyncCompileJob still exists when the stream wants to call it. With
this CL we add an additional level of defense to make sure that
streaming does not continue after the AsyncCompileJob got destructed.

It is not clear if this CL fixes the bug referenced below. However, the
crashes there could be caused when streaming accesses the
AsyncCompileJob after it got destructed already. I was not able though
to find a scenario where this is possible.

R=clemensh@chromium.org

Bug: chromium:888170
Change-Id: Id5c6cc34842735a3adaf3e09c57cbe923cfc2630
Reviewed-on: https://chromium-review.googlesource.com/1241961
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56213}

This CL makes UnoptimizedCompilationJob a simple proxy for
BackgroundCompilerTask. A follow-up CL will remove UnoptimizedCompilationJob
entirely and have CompilerDispatcher deal directly with BackgroundCompilerTasks

BUG=v8:8041, v8:8015

Change-Id: Ia53d05c015c4ca2ee32a4d1c5d0c65edb3caeda8
Reviewed-on: https://chromium-review.googlesource.com/1236257
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56212}

Create LdaNamedPropertyNoFeedback and StaNamedPropertyNoFeedback
for one-shot property loads and stores. This CL replaces the runtime
calls with new bytecodes for named property load stores in one-shot code.
the runtime calls needed extra set of consecutive registers and
additional move instructions. This increased the size of
bytecode-array and possibly extended the life time of objects.
By replacing them with NoFeedback bytecodes we avoid these issues.

Bug: v8:8072
Change-Id: I20a38a5ce9940026171d870d354787fe0b7c5a6f
Reviewed-on: https://chromium-review.googlesource.com/1196725Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Chandan Reddy <chandanreddy@google.com>
Cr-Commit-Position: refs/heads/master@{#56211}

The WASM engine compiles per-import wrappers for callables imported
into a WASM instance that have one of a number of different shapes,
depending on the type of the imported function and whether there is
a signature match. This CL introduces an enum with a value for each
case in preparation for introducing a per-kind cache.

R=mstarzinger@chromium.org
CC=clemensh@chromium.org

Change-Id: If9b7355ff7c57a329c096f93f3624bc3d6c74e3f
Reviewed-on: https://chromium-review.googlesource.com/1243045
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56210}

This fast path copies the backing store and replaces holes with undefined.
In the case where the array is holey but there is no actual holes, the
resulting array is of the same elements kind as the source array. If a hole
does appear, the resulting array will be of PACKED_ELEMENTS kind so that it
can contain undefined.

The builtin CloneFastJSArrayFillingHoles includes this fast path, but
CloneFastJSArray does not (it still behaves as before). In case of fast
packed arrays, CloneFastJSArrayFillingHoles behaves the same as
CloneFastJSArray.

Bug: chromium:881273, v8:7980
Change-Id: I49c641c1a673313f06aeed93077031ab6b017b6d
Reviewed-on: https://chromium-review.googlesource.com/1236573
Commit-Queue: Hai Dang <dhai@google.com>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56209}

CHECK_OK is a macro that checks whether the function failed, and returns a
dummy expression if it did to avoid continuing parsing. If we're immediately
returning the result of the call anyway we don't need the additional check and
can just return whatever the call returned.

Change-Id: I0da1a6a4440728ce14923c57f52522ac93da6b8e
Reviewed-on: https://chromium-review.googlesource.com/1242805Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56208}

It deals with strict-mode but is in a branch guarded by is_sloppy.

Change-Id: I309c187a96b5fa62956eec5bb05f50c0ce4e5ad3
Reviewed-on: https://chromium-review.googlesource.com/1243105
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56207}

This is just a cleanup.

Bug: v8:7790
Change-Id: Ic0114451159b8c504f527f3cf3bdaed6a8cc8741
Reviewed-on: https://chromium-review.googlesource.com/1243103
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56206}

... if FLAG_concurrent_compiler_frontend is enabled.

Bug: v8:7790
Change-Id: I448560b21d54c8907e8cbf68bdaf8bbdf2b034df
Reviewed-on: https://chromium-review.googlesource.com/1241959Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56205}

First step towards GC of wasm code: Introduce a link to all Isolates
that use a WasmEngine.

R=mstarzinger@chromium.org

Bug: v8:8217
Change-Id: Ib7f4495e7c7e5cc9ad58293518c65738f23d664c
Reviewed-on: https://chromium-review.googlesource.com/1240335
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56204}

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

No-Try: true
Bug: v8:7793
Change-Id: Ia47ecf83b80decc5e04b170c2a492a8365a87346
Reviewed-on: https://chromium-review.googlesource.com/1243043
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56203}

Bug: v8:7793
Change-Id: I18bd30b36be3c3f89962a2e9c04d8f159c8cfe2b
Reviewed-on: https://chromium-review.googlesource.com/1240415
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56202}

This is a reland of 31228a69

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

Original change's description:
> [Compile] Refactor BackgroundCompileTask to enable its use by CompilerDispatcher
>
> Splits background compilation data out of ScriptStreamingData and into
> BackgroundCompileTask. Also makes BackgroundCompileTask no longer a sub-class
> of ScriptStreamingTask, and instead have ScriptStreamingTask delegate to a
> BackgroundCompileTask.
>
> As part of this change, we now create the CharacterStream on the main thread,
> and therefore have to set the (thread-local) runtime_call_stats on the already
> created CharacterStream when the BackgroundCompileTask is run on the background
> thread. As such, changes to CharacterStream were needed to feed the
> runtime_call_stats through appropriately.
>
> Deprecates Source::GetCachedData and StreamedSource::GetCachedData since they are
> no longer used, and the streamed source never has cached data (streaming is
> suppressed if cached data is available). Also removes Utf8ChunkedStream which
> is dead code.
>
> BUG=v8:8041, v8:8015
> TBR=yangguo@chromium.org
>
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: Ifcc723ebf930a1dc01135fcb70929d6168471cb3
> Reviewed-on: https://chromium-review.googlesource.com/1236353
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56182}

Bug: v8:8041, v8:8015
Change-Id: Ied5132c537d4c25c6e355f289c2a9cc1f8ff98e9
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1242097
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56201}

Emit call node instead of soft-deopt for CallNoFeedback to
avoid performance penalty incase one-shot code gets optimized.
Tweek the inling heuristic to avoid recurisve inling with stress-opt.

Bug: v8:8106, v8:8072
Change-Id: I09643c0648b6c880f491d08a8a73f1960ca999c0
Reviewed-on: https://chromium-review.googlesource.com/1239075Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Chandan Reddy <chandanreddy@google.com>
Cr-Commit-Position: refs/heads/master@{#56200}

BUG=v8:5402,v8:8015

Change-Id: I4afa8ada312df691b06c2d107fd5254c0fbb9496
Reviewed-on: https://chromium-review.googlesource.com/1238577Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56199}

R=clemensh@chromium.org

Change-Id: Iabbef9d054671ec11a48321bb4e75a49084560ed
Reviewed-on: https://chromium-review.googlesource.com/1238925Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56198}

R=yangguo@chromium.org

Bug: chromium:872783, v8:8015
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I2d281ba058961ebe2e2758e90b4afa34b02fd5b1
Reviewed-on: https://chromium-review.googlesource.com/1216004Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56197}

Bug: v8:6666
Change-Id: I5af95a3e9dcffb4be26a8ffd2948784d2910d64a
Reviewed-on: https://chromium-review.googlesource.com/1242804Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56196}

This CL ensures that kRootRegister (ebx) is preserved in
BailoutOfDeoptimized and PopArgumentsAdaptorFrame.

This CL uses push/pop to preserve eax, even though it is not used in
OPTIMIZED_FUNCTION code. If we must get more performance, we might be
able to get rid of push/pop, but I've left it in because it is cleaner
code this way. Another alternative is to use ecx in case of embedded
builtins only (as it is used for speculation in the standard config).

Change-Id: I437c8754408414d82b2fbd8b33d2faeda17aee30
Bug: v8:6666
Reviewed-on: https://chromium-review.googlesource.com/1242886
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56195}

Cherry-picked from cd285951 for arm64 only, with a small addition.

Change-Id: I864f811e7fe5cb47390e6a0588b48d057ccb6292
Reviewed-on: https://chromium-review.googlesource.com/1240334Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#56194}

Part of it was already obsolete. The other part, concerned with
typing, is moved to the TyperPhase.

Bug: v8:7790
Change-Id: If728b36d88d19ded26d818eb805d093942576fcd
Reviewed-on: https://chromium-review.googlesource.com/1242884Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56193}

This CL addresses comments left post-merge on
https://crrev.com/c/1238653
which improve readablity.

R=jarin@chromium.org

Bug: v8:6666, v8:8015
Change-Id: Idafd848dafdd97af525646d6321e0ca40ce856c5
Reviewed-on: https://chromium-review.googlesource.com/1242885Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56192}

The existing script source tracking was racing with general external
script resource tracking, resulting in heap-order-dependent labels.

Bug: v8:8218
Change-Id: Ib09c28ca1e13768b328ecef7f8ee3ea5131ba12e
Reviewed-on: https://chromium-review.googlesource.com/1238927Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56191}

Change-Id: I4cffe3d595aa3b3d85d4c45d5bb9654728c9137b
Reviewed-on: https://chromium-review.googlesource.com/1238923
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56190}

This is a regression test for a really specific issue that is flaky.
We should just disable it for all configurations rather than wait for
extra flakes which we then have to diagnose.

Bug: v8:8209
Change-Id: I976f2d7cdd92f3ce5c7eb9fd28976201d1d6612f
Reviewed-on: https://chromium-review.googlesource.com/1240120Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56189}

R=titzer@chromium.org

Change-Id: I6eabacf07e3dd95d1bec68f1980ec6aae5220c97
Reviewed-on: https://chromium-review.googlesource.com/1238926Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56188}

This reverts commit 31228a69.

Reason for revert: Introduces new pretty consistent flakes on Linux sanitizers, one of which block LKGR. Please see https://crbug.com/v8/8219

Original change's description:
> [Compile] Refactor BackgroundCompileTask to enable its use by CompilerDispatcher
> 
> Splits background compilation data out of ScriptStreamingData and into
> BackgroundCompileTask. Also makes BackgroundCompileTask no longer a sub-class
> of ScriptStreamingTask, and instead have ScriptStreamingTask delegate to a
> BackgroundCompileTask.
> 
> As part of this change, we now create the CharacterStream on the main thread,
> and therefore have to set the (thread-local) runtime_call_stats on the already
> created CharacterStream when the BackgroundCompileTask is run on the background
> thread. As such, changes to CharacterStream were needed to feed the
> runtime_call_stats through appropriately.
> 
> Deprecates Source::GetCachedData and StreamedSource::GetCachedData since they are
> no longer used, and the streamed source never has cached data (streaming is
> suppressed if cached data is available). Also removes Utf8ChunkedStream which
> is dead code.
> 
> BUG=v8:8041, v8:8015
> TBR=yangguo@chromium.org
> 
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: Ifcc723ebf930a1dc01135fcb70929d6168471cb3
> Reviewed-on: https://chromium-review.googlesource.com/1236353
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56182}

TBR=rmcilroy@chromium.org,yangguo@chromium.org,verwaest@chromium.org

Change-Id: Ib05bcbde2e9a588bd4008d2155f75cdac5cc47f5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8041, v8:8015
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1241958Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56187}

This reverts commit f2f48bd8.

Reason for revert: Negative performance impact

Original change's description:
> [parser] Restructure Binary expression parsing
> 
> Change-Id: I1ff35a3e647b32edb229f47fde80de1b8b50737b
> Reviewed-on: https://chromium-review.googlesource.com/1240333
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56179}

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

Change-Id: If08f8c5f538dc25f5f3ea62cd8dd80e024156e81
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/1241957Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56186}

Wasm modules can now grow up to 1024 MB. Bump the maximum of the
corresponding histogram so we record the full range.

R=titzer@chromium.org

Change-Id: I984b2314fcb41435f300df6e8f63b62c096d1330
Reviewed-on: https://chromium-review.googlesource.com/1240337Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56185}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/dfca77b..4325c99

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/868fbbf..c51eb62

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/baf0927..64b6133

Rolling v8/third_party/fuchsia-sdk: https://chromium.googlesource.com/chromium/src/third_party/fuchsia-sdk/+log/dc90d99..9b435fc

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

Change-Id: I6582dfcb56e4f1dbfdd32ea32134044c76dd339d
Reviewed-on: https://chromium-review.googlesource.com/1242603Reviewed-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@{#56184}

Change-Id: I554c028627c4032d7c47e8d6d6a6ed4e4a38d0a5
Reviewed-on: https://chromium-review.googlesource.com/1241474Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56183}

Splits background compilation data out of ScriptStreamingData and into
BackgroundCompileTask. Also makes BackgroundCompileTask no longer a sub-class
of ScriptStreamingTask, and instead have ScriptStreamingTask delegate to a
BackgroundCompileTask.

As part of this change, we now create the CharacterStream on the main thread,
and therefore have to set the (thread-local) runtime_call_stats on the already
created CharacterStream when the BackgroundCompileTask is run on the background
thread. As such, changes to CharacterStream were needed to feed the
runtime_call_stats through appropriately.

Deprecates Source::GetCachedData and StreamedSource::GetCachedData since they are
no longer used, and the streamed source never has cached data (streaming is
suppressed if cached data is available). Also removes Utf8ChunkedStream which
is dead code.

BUG=v8:8041, v8:8015
TBR=yangguo@chromium.org

Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: Ifcc723ebf930a1dc01135fcb70929d6168471cb3
Reviewed-on: https://chromium-review.googlesource.com/1236353
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56182}

Rolling v8/third_party/icu: https://chromium.googlesource.com/chromium/deps/icu/+log/7ca3ffa..c52a2a2

This includes fixes from https://crrev.com/c/1240414.

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

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I2afd319dbb244356a9bb057eb80c5fb0310b8686
Reviewed-on: https://chromium-review.googlesource.com/1240106Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56181}

Change-Id: I05db378984b583d9dff3fe9fceb3adbf7e046e20
Reviewed-on: https://chromium-review.googlesource.com/1240338Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56180}