Original commit message:
[wasm] Introduce the TrapIf and TrapUnless operators to generate trap code.

Some instructions in WebAssembly trap for some inputs, which means that the
execution is terminated and (at least at the moment) a JavaScript exception is
thrown. Examples for traps are out-of-bounds memory accesses, or integer
divisions by zero.

Without the TrapIf and TrapUnless operators trap check in WebAssembly introduces 5
TurboFan nodes (branch, if_true, if_false, trap-reason constant, trap-position
constant), in addition to the trap condition itself. Additionally, each
WebAssembly function has four TurboFan nodes (merge, effect_phi, 2 phis) whose
number of inputs is linear to the number of trap checks in the function.
Especially for functions with high numbers of trap checks we observe a
significant slowdown in compilation time, down to 0.22 MiB/s in the sqlite
benchmark instead of the average of 3 MiB/s in other benchmarks. By introducing
a TrapIf common operator only a single node is necessary per trap check, in
addition to the trap condition. Also the nodes which are shared between trap
checks (merge, effect_phi, 2 phis) would disappear. First measurements suggest a
speedup of 30-50% on average.

This CL only implements TrapIf and TrapUnless on x64. The implementation is also
hidden behind the --wasm-trap-if flag.

Please take a special look at how the source position is transfered from the
instruction selector to the code generator, and at the context that is used for
the runtime call.

R=titzer@chromium.org, v8-mips-ports@googlegroups.com

Review-Url: https://codereview.chromium.org/2628433004
Cr-Commit-Position: refs/heads/master@{#42230}

Review-Url: https://codereview.chromium.org/2626013002
Cr-Commit-Position: refs/heads/master@{#42229}

for debugging. This function is needed to pass increased heap limit
from the main DevTools isolate to the worker isolates it spawns.

BUG=chromium:675911

Review-Url: https://codereview.chromium.org/2624973003
Cr-Commit-Position: refs/heads/master@{#42228}

BUG=chromium:676635

Review-Url: https://codereview.chromium.org/2628853002
Cr-Commit-Position: refs/heads/master@{#42227}

BUG=

Review-Url: https://codereview.chromium.org/2621303002
Cr-Commit-Position: refs/heads/master@{#42226}

This API will allow DevTools to intercept out-of-memory condition,
increase the heap limit and schedule heap snapshot.

BUG=chromium:675911

Review-Url: https://codereview.chromium.org/2621873003
Cr-Commit-Position: refs/heads/master@{#42225}

This changes the BytecodeGraphBuilder interface to make the fact that
graph construction is independent of a closure explicit. A valid graph
can be constructed by providing only the pair of statically known values
for SharedFunctionInfo and TypeFeedbackVector. This is in preparation of
inlining based on the SharedFunctionInfo.

R=jarin@chromium.org
BUG=v8:2206

Review-Url: https://codereview.chromium.org/2626623002
Cr-Commit-Position: refs/heads/master@{#42224}

This is mainly to catch a crash that we see in Canary with escape
analysis on.

Review-Url: https://codereview.chromium.org/2625893003
Cr-Commit-Position: refs/heads/master@{#42223}

Revert of [wasm] Enable WASM by default (--expose-wasm=true). (patchset #3 id:40001 of https://codereview.chromium.org/2623743003/ )

Reason for revert:
layout test breakages:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/12574

revert first to unblock rolling. otherwise please rebaseline.

Original issue's description:
> [wasm] Enable WASM by default (--expose-wasm=true).
>
> BUG=chromium:575167
> R=rossberg@chromium.org,ahaas@chromium.org,clemensh@chromium.org,bradnelson@chromium.org
>
> Review-Url: https://codereview.chromium.org/2623743003
> Cr-Original-Commit-Position: refs/heads/master@{#42197}
> Committed: https://chromium.googlesource.com/v8/v8/+/34b63f050b1a247bb64ddc91c967501ce04e011f
> Review-Url: https://codereview.chromium.org/2623743003
> Cr-Commit-Position: refs/heads/master@{#42214}
> Committed: https://chromium.googlesource.com/v8/v8/+/71f5650828ffd0162fcd67d9c6ef570a346a8a84

TBR=clemensh@chromium.org,ahaas@chromium.org,bradnelson@chromium.org,rossberg@chromium.org,bradnelson@google.com,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:575167

Review-Url: https://codereview.chromium.org/2621323002
Cr-Commit-Position: refs/heads/master@{#42222}

This CL modifies the ast-numbering phase to collect function literals which
should be compiled eagerly. This is then used to eagerly compile the inner
functions before compiling the outer function. This will be used to queue
compilation jobs on the CompilerDispatcher in a later CL.

This CL moves the compilation of eager inner functions out of the
GetSharedFunctionInfo function and instead compiles them explicitly. This
simplifies GetSharedFunctionInfo and also means there is no need to pass a
LazyCompilationMode to the function, so this concept has been removed.

BUG=v8:5203,v8:5215

Review-Url: https://codereview.chromium.org/2618553004
Cr-Commit-Position: refs/heads/master@{#42221}

R=jgruber@chromium.org
BUG=v8:5530

Review-Url: https://codereview.chromium.org/2589203002
Cr-Original-Commit-Position: refs/heads/master@{#41911}
Committed: https://chromium.googlesource.com/v8/v8/+/381082168d37d4f2794360ae31dc078f2a350113
Review-Url: https://codereview.chromium.org/2589203002
Cr-Commit-Position: refs/heads/master@{#42220}

This has been broken since forever.

BUG=v8:5669

Review-Url: https://codereview.chromium.org/2610343002
Cr-Commit-Position: refs/heads/master@{#42219}

Most notably, the interpreter now calls this stub instead of the
runtime.

BUG=

Review-Url: https://codereview.chromium.org/2619163004
Cr-Commit-Position: refs/heads/master@{#42218}

BUG=chromium:680064
TBR=clemensh@chromium.org, titzer@chromium.org, ahaas@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2620333002
Cr-Commit-Position: refs/heads/master@{#42217}

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2624113002
Cr-Commit-Position: refs/heads/master@{#42216}

Also suppress a testcase using f.arguments.

BUG=chromium:662424
TBR=jarin@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2625983002
Cr-Commit-Position: refs/heads/master@{#42215}

BUG=chromium:575167
R=rossberg@chromium.org,ahaas@chromium.org,clemensh@chromium.org,bradnelson@chromium.org

Review-Url: https://codereview.chromium.org/2623743003
Cr-Original-Commit-Position: refs/heads/master@{#42197}
Committed: https://chromium.googlesource.com/v8/v8/+/34b63f050b1a247bb64ddc91c967501ce04e011f
Review-Url: https://codereview.chromium.org/2623743003
Cr-Commit-Position: refs/heads/master@{#42214}

and rename WasmFrame to WasmCompiledFrame.
The WasmToInterpreterFrames are not used yet; this will follow in a
follow-up CL (see tracking bug for the overall picture).
Those frames will represent frames for WASM_TO_INTERPRETER stubs, which
call from wasm code to the wasm interpreter, implemented in C++.
They will support the Summarize method to inspect the stack frames in
the wasm interpreter.

R=yangguo@chromium.org, titzer@chromium.org
BUG=v8:5822

Review-Url: https://codereview.chromium.org/2623773004
Cr-Commit-Position: refs/heads/master@{#42213}

Revert of Internalize strings in-place (patchset #17 id:320001 of https://codereview.chromium.org/2549773002/ )

Reason for revert:
blocks roll, see: https://codereview.chromium.org/2628733002/

Debug mode runs into an Abort("External string expected, but not found").

Original issue's description:
> Internalize strings in-place (reland)
>
> using newly introduced ThinStrings, which store a pointer to the actual,
> internalized string they represent.
>
> BUG=v8:4520
>
> (Previously landed as #42168 / af51befe.
>
> Review-Url: https://codereview.chromium.org/2549773002
> Cr-Commit-Position: refs/heads/master@{#42193}
> Committed: https://chromium.googlesource.com/v8/v8/+/4c699e349a4986b28574b3a51e8780e3a3d067b1

TBR=ishell@chromium.org,hpayer@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4520

Review-Url: https://codereview.chromium.org/2625073002
Cr-Commit-Position: refs/heads/master@{#42212}

BUG=chromium:679957
NOTRY=true
TBR=jarin@chromium.org,bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2628813002
Cr-Commit-Position: refs/heads/master@{#42211}

Lower StoreDataPropertyInLiteral() when storing
computed property names in object literals.

Add a new AccessMode, kStoreInLiteral. It is similar to
AccessMode::kStore but does not look
up properties on the prototype chain.

99% of all literal definitions with computed property names
end up with generic access_info because of how we count
properties. Once we fix
https://bugs.chromium.org/p/v8/issues/detail?id=5625,
they'll get lowered as well.

BUG=v8:5624

Review-Url: https://codereview.chromium.org/2619773002
Cr-Commit-Position: refs/heads/master@{#42210}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/da5025b..91344e6

Rolling v8/third_party/catapult: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+log/886ff59..8b10e78

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

Review-Url: https://codereview.chromium.org/2622133002
Cr-Commit-Position: refs/heads/master@{#42209}

  port 0c4b8ff4 (r42192)

  original commit message:
   - Refactor Dispatch tables to have separate function, signature tables
   - New Relocation type for WasmFunctionTableReference, assembler, compiler support.
   - RelocInfo helper functions for Wasm references

BUG=

Review-Url: https://codereview.chromium.org/2623133002
Cr-Commit-Position: refs/heads/master@{#42208}

R=bradnelson@chromium.org
BUG=v8:5809

Review-Url: https://codereview.chromium.org/2625853003
Cr-Commit-Position: refs/heads/master@{#42207}

BUG=v8:5816

Review-Url: https://codereview.chromium.org/2626693002
Cr-Commit-Position: refs/heads/master@{#42206}

Also ensuring it is validation error to specify more than
one memory import.

BUG=v8:5824

Review-Url: https://codereview.chromium.org/2624853002
Cr-Commit-Position: refs/heads/master@{#42205}

Asm.js warnings / info is non-canonical.
It may be useful to suppress it in golden file tests
(for instance LayoutTests).

BUG=v8:4203
R=mtrofin@chromium.org

Review-Url: https://codereview.chromium.org/2625833003
Cr-Commit-Position: refs/heads/master@{#42204}

It shipped with Chrome 55 stable.

R=littledan@chromium.org

Review-Url: https://codereview.chromium.org/2621173002
Cr-Commit-Position: refs/heads/master@{#42203}

Port 4c699e34

Original Commit Message:

    using newly introduced ThinStrings, which store a pointer to the actual,
    internalized string they represent.

    (Previously landed as #42168 / af51befe.

R=jkummerow@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4520
LOG=N

Review-Url: https://codereview.chromium.org/2628643002
Cr-Commit-Position: refs/heads/master@{#42202}

Port 0c4b8ff4

Original Commit Message:

     - Refactor Dispatch tables to have separate function, signature tables
     - New Relocation type for WasmFunctionTableReference, assembler, compiler support.
     - RelocInfo helper functions for Wasm references

R=gdeepti@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2625683004
Cr-Commit-Position: refs/heads/master@{#42201}

Revert of [wasm][asm.js] Enable --validate-asm by default. (patchset #1 id:1 of https://codereview.chromium.org/2624813002/ )

Reason for revert:
Breaks layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/12554

See also:
https://github.com/v8/v8/wiki/Blink%20layout%20tests

Original issue's description:
> [wasm][asm.js] Enable --validate-asm by default.
>
> This directs all asm.js traffic via the Wasm backend.
>
> R=titzer@chromium.org,aseemgarg@chromium.org
> BUG=v8:4203
>
> Review-Url: https://codereview.chromium.org/2624813002
> Cr-Commit-Position: refs/heads/master@{#42194}
> Committed: https://chromium.googlesource.com/v8/v8/+/946cc371ed4b34d1a9f5cc615b14c41b652562ad

TBR=aseemgarg@chromium.org,titzer@chromium.org,bradnelson@google.com,bradnelson@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4203

Review-Url: https://codereview.chromium.org/2622023002
Cr-Commit-Position: refs/heads/master@{#42200}

Revert of [wasm] Enable WASM by default (--expose-wasm=true). (patchset #2 id:20001 of https://codereview.chromium.org/2623743003/ )

Reason for revert:
arm64 gc stress:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20gc%20stress/builds/4424

Original issue's description:
> [wasm] Enable WASM by default (--expose-wasm=true).
>
> BUG=chromium:575167
> R=rossberg@chromium.org,ahaas@chromium.org,clemensh@chromium.org,bradnelson@chromium.org
>
> Review-Url: https://codereview.chromium.org/2623743003
> Cr-Commit-Position: refs/heads/master@{#42197}
> Committed: https://chromium.googlesource.com/v8/v8/+/34b63f050b1a247bb64ddc91c967501ce04e011f

TBR=clemensh@chromium.org,ahaas@chromium.org,bradnelson@chromium.org,rossberg@chromium.org,bradnelson@google.com,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:575167

Review-Url: https://codereview.chromium.org/2626763002
Cr-Commit-Position: refs/heads/master@{#42199}

TBR=bmeurer@chromium.org
NOTRY=true
NOTREECHECKS=true

Review-Url: https://codereview.chromium.org/2621123002
Cr-Commit-Position: refs/heads/master@{#42198}

BUG=chromium:575167
R=rossberg@chromium.org,ahaas@chromium.org,clemensh@chromium.org,bradnelson@chromium.org

Review-Url: https://codereview.chromium.org/2623743003
Cr-Commit-Position: refs/heads/master@{#42197}

This is a follow-up on 45c11887, which
removed hole checks from full-codegen. Variables requiring hole checks
always go through Ignition.

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2622783002
Cr-Commit-Position: refs/heads/master@{#42196}

BUG=
R=clemensh@chromium.org,verwaest@chromium.org

Review-Url: https://codereview.chromium.org/2627453006
Cr-Commit-Position: refs/heads/master@{#42195}

This directs all asm.js traffic via the Wasm backend.

R=titzer@chromium.org,aseemgarg@chromium.org
BUG=v8:4203

Review-Url: https://codereview.chromium.org/2624813002
Cr-Commit-Position: refs/heads/master@{#42194}

using newly introduced ThinStrings, which store a pointer to the actual,
internalized string they represent.

BUG=v8:4520

(Previously landed as #42168 / af51befe.

Review-Url: https://codereview.chromium.org/2549773002
Cr-Commit-Position: refs/heads/master@{#42193}

 - Refactor Dispatch tables to have separate function, signature tables
 - New Relocation type for WasmFunctionTableReference, assembler, compiler support.
 - RelocInfo helper functions for Wasm references

Review-Url: https://codereview.chromium.org/2627543003
Cr-Commit-Position: refs/heads/master@{#42192}

Asm.js modules missing exports fail to run the last phase of
validation. Adding an explicit check for this.

BUG=676573
R=titzer@chromium.org,aseemgarg@chromium.org

Review-Url: https://codereview.chromium.org/2620893002
Cr-Commit-Position: refs/heads/master@{#42191}