port 1e00bb57 (r30737).

original commit message:

    (reason for revert/reland: patch incorrectly left --vector-stores flag
     on, helpfully revealing some gcstress issues to look at, but they
     don't need to block this CL).

    Some pretty hacky code was used to carry out the tail-call
    handler dispatch on ia32 vector stores due to a lack
    of free registers. It really tanks performance. A better
    approach is to use a virtual register on the isolate.

BUG=

Review URL: https://codereview.chromium.org/1344383002

Cr-Commit-Position: refs/heads/master@{#30781}

port 54bab695 (r30747).

original commit message:

    Move the implementation of the Abstract Equality Comparison to the
    runtime and thereby remove the EQUALS dispatcher builtin. Also remove
    the various runtime entry points that were only used to support the
    EQUALS builtin.

    Now the Abstract Equality Comparison is also using the correct
    ToPrimitive implementation, which properly supports @@toPrimitive.

BUG=

Review URL: https://codereview.chromium.org/1349623002

Cr-Commit-Position: refs/heads/master@{#30780}

TBR=bmeurer,yurys
NOTRY=true

Review URL: https://codereview.chromium.org/1349953002

Cr-Commit-Position: refs/heads/master@{#30779}

Add an assertion that allocated_bytes >= 0 in IncrementalMark::Step and then
make it pass. We were not being diligent in maintaining top_on_previous_step_
and as a result inaccurate, and even negative values of allocated_bytes were
being reported to Step.

BUG=
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1274453002

Cr-Commit-Position: refs/heads/master@{#30778}

Upon collection of the stack trace if the current PC falls into
the frame building code, the top frame might be in a non-consistent
state. That leads to some of the frames could be missing from the
stack trace.

The patch makes it check instructions under current PC and if they
look like the frame setup/destroy code, it skips the entire sample.

Support for x86/x64

BUG=chromium:529931
LOG=N

Review URL: https://codereview.chromium.org/1341413002

Cr-Commit-Position: refs/heads/master@{#30777}

This is a performance bug, not a functional bug: we were
losing grouping opportunities.

BUG=

Review URL: https://codereview.chromium.org/1342243003

Cr-Commit-Position: refs/heads/master@{#30776}

Some cleanup of ParsePropertyDefinition --- Replaces certain hacks with
more structured, clean code, and adds additional comments to aid in
comprehension of this tricky area of the ambiguous recursive descent
parser.

BUG=v8:3583
LOG=N
R=adamk, aperez, wingo, rossberg

Review URL: https://codereview.chromium.org/1348773004

Cr-Commit-Position: refs/heads/master@{#30775}

We already disallowed observing the global proxy; now we also
disallow any observation of access-checked objects (regardless
of whether the access check would succeed or fail, since there's
not a good way to tell the embedder what kind of access is being
requested).

Also disallow Object.getNotifier for the same reasons.

BUG=chromium:531891
LOG=y

Review URL: https://codereview.chromium.org/1346813002

Cr-Commit-Position: refs/heads/master@{#30774}

This adds a utils object meant specifically for V8 extras, presenting a limited
API surface for doing things that would otherwise require %-functions.

BUG=v8:4276
LOG=Y
R=jochen@chromium.org,yangguo@chromium.org

Review URL: https://codereview.chromium.org/1343113003

Cr-Commit-Position: refs/heads/master@{#30773}

Defines a new --harmony-tolength flag, and a ToLengthFlagged() runtime function,
that is used where ES6 requires ToLength(), but a pre-ES6 conversion existed
before. When the flag is disabled, the function uses TO_UINT32(), which is
the pre-ES6 behaviour. When the flag enabled, the ES6-compliant ToLength()
conversion is used.

Based on a patch initially from Diego Pino <dpino@igalia.com>

BUG=v8:3087
LOG=Y

Review URL: https://codereview.chromium.org/1309243003

Cr-Commit-Position: refs/heads/master@{#30772}

ArrayBuffer's backing store is a pointer to external heap, and can't be
treated as a heap object. Doing so will result in crashes, when the
backing store is unaligned.

See: https://github.com/nodejs/node/issues/2791

BUG=chromium:530531
R=mlippautz@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1327403002

Cr-Commit-Position: refs/heads/master@{#30771}

````
var array = new Uint8Array(65000);
var startDate = Date.now();
var counter = 0;
while (counter++ < 50000000) {
  array.subarray(start, end);
}
var endDate = Date.now();
print(endDate - startDate);
````

4200 ms -> 3500 ms (16.67%)

BUG=

Review URL: https://codereview.chromium.org/1331993004

Cr-Commit-Position: refs/heads/master@{#30770}

Add support for `get` and `set` as shorthand properties. Also
supports them for CoverInitializedName in BindingPatterns and (once implemented)
AssignmentPatterns.

BUG=v8:4412, v8:3584
LOG=N
R=adamk, aperez, wingo, rossberg

Review URL: https://codereview.chromium.org/1328083002

Cr-Commit-Position: refs/heads/master@{#30769}

This will catch an invalid receiver before being passed to a load ic miss
handler in the runtime.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1351493002

Cr-Commit-Position: refs/heads/master@{#30768}

There isn't a plan to turn it on soon, so we'll take it out in favor of cleaner code.

BUG=

Review URL: https://codereview.chromium.org/1202173002

Cr-Commit-Position: refs/heads/master@{#30767}

This makes sure that the arguments object materialization in the method
prologue is composable with respect to inlining. The generic runtime
functions materializing those objects now respect the deoptimization
information when reconstructing the original arguments.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1340313003

Cr-Commit-Position: refs/heads/master@{#30766}

Fixing floating point register clobbering for MIPSr6 (32 and 64)
due to using of f31 floating point register as double compare register,
without saving the value of the register before using it.

TEST=cctest/test-debug/*
BUG=

Review URL: https://codereview.chromium.org/1346623002

Cr-Commit-Position: refs/heads/master@{#30765}

Review URL: https://codereview.chromium.org/1348073002

Cr-Commit-Position: refs/heads/master@{#30764}

BUG=v8:4422
R=jochen@chromium.org
LOG=Y

Review URL: https://codereview.chromium.org/1346613002

Cr-Commit-Position: refs/heads/master@{#30763}

No need to rely on the %_IsConstructCall magic here, we can just
implement the Symbol constructor in C++ altogether (it was just a
stupid wrapper around %CreateSymbol anyway).

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1349643002

Cr-Commit-Position: refs/heads/master@{#30762}

This adds debug code that makes sure that the runtime functions that
materialize arguments objects, {Runtime_New[Sloppy|Strict]Arguments},
are not being called from within an inlined scope. They would produce
wrong results and we should avoid producing code that does this.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1343763002

Cr-Commit-Position: refs/heads/master@{#30761}

Adds concurrency support for:
- MemoryChunk: Fragmentation counters
- MemoryChunk: High-water mark
- MemoryAllocator: Lowest and highest ever allocated addresses, size, and
  capacity

R=hpayer@chromium.org
BUG=chromium:524425
LOG=N

This reverts commit 0db34dbe.

BUG=

Review URL: https://codereview.chromium.org/1346973002

Cr-Commit-Position: refs/heads/master@{#30760}

Implement the String constructor completely as native builtin,
avoiding the need to do gymnastics in JavaScript builtin to
properly detect the no argument case (which is different from
the undefined argument case) and also allowing to just
tailcall through to ToString or SymbolDescriptiveString for
the common case. Also the JavaScript builtin was misleading
since the case for construct call was unused, but could be
triggered in a wrong way once we support tail calls from
constructor functions.

This refactoring allows us to properly implement subclassing
for String builtins, once we have the correct initial_map on
derived classes (it's merely a matter of using NewTarget
instead of the target register now).

This introduces a new %SymbolDescriptiveString runtime
entry, which is also used by Symbol.toString() now.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1344893002

Cr-Commit-Position: refs/heads/master@{#30759}

BUG=v8:4423
LOG=N

Review URL: https://codereview.chromium.org/1342013003

Cr-Commit-Position: refs/heads/master@{#30758}

R=hpayer@chromium.org
BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/1350633003

Cr-Commit-Position: refs/heads/master@{#30757}

Same as https://codereview.chromium.org/1340303002/

BUG=

Review URL: https://codereview.chromium.org/1339763005

Cr-Commit-Position: refs/heads/master@{#30756}

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1318713007

Cr-Commit-Position: refs/heads/master@{#30755}

Mark ArrayLiterals utilizing the spread operator as non-simple.
This causes them to return false for IsCompileTimeValue, and thus
causes spread to work as expected in nested literals.

BUG=v8:4417
LOG=y

Review URL: https://codereview.chromium.org/1336123002

Cr-Commit-Position: refs/heads/master@{#30754}

Review URL: https://codereview.chromium.org/1340303002

Cr-Commit-Position: refs/heads/master@{#30753}

Revert of [heap] Concurrency support for heap book-keeping info (patchset #4 id:60001 of https://codereview.chromium.org/1340923004/ )

Reason for revert:
crashing: http://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%20debug%20-%203/builds/4716

Original issue's description:
> [heap] Concurrency support for heap book-keeping info.
>
> Adds concurrency support for:
> - MemoryChunk: Fragmentation counters
> - MemoryChunk: High-water mark
> - MemoryAllocator: Lowest and highest ever allocated addresses, size, and
>   capacity
>
> R=hpayer@chromium.org
> BUG=chromium:524425
> LOG=N
>
> Committed: https://crrev.com/63190721cda4966e01d71e92a730ce48ea789fbc
> Cr-Commit-Position: refs/heads/master@{#30749}

TBR=hpayer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:524425

Review URL: https://codereview.chromium.org/1340323002

Cr-Commit-Position: refs/heads/master@{#30752}

Loads get an acquire, store/cas a release. Increment gets a full barrier.

R=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1343883004

Cr-Commit-Position: refs/heads/master@{#30751}

The ES6 specification says that "Built-in functions that are ECMAScript
function objects must be strict mode functions", which in particular
means that you can never test for them using the "caller" field of a
sloppy mode function.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg
R=mstarzinger@chromium.org
BUG=v8:105
LOG=n

Review URL: https://codereview.chromium.org/1347663002

Cr-Commit-Position: refs/heads/master@{#30750}

Adds concurrency support for:
- MemoryChunk: Fragmentation counters
- MemoryChunk: High-water mark
- MemoryAllocator: Lowest and highest ever allocated addresses, size, and
  capacity

R=hpayer@chromium.org
BUG=chromium:524425
LOG=N

Review URL: https://codereview.chromium.org/1340923004

Cr-Commit-Position: refs/heads/master@{#30749}

Previously the mutex only guarded free_list_. The extension covers also
allocation_list_.

BUG=chromium:524425
LOG=N

Review URL: https://codereview.chromium.org/1341293002

Cr-Commit-Position: refs/heads/master@{#30748}

Move the implementation of the Abstract Equality Comparison to the
runtime and thereby remove the EQUALS dispatcher builtin. Also remove
the various runtime entry points that were only used to support the
EQUALS builtin.

Now the Abstract Equality Comparison is also using the correct
ToPrimitive implementation, which properly supports @@toPrimitive.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg
R=mstarzinger@chromium.org
BUG=v8:4307
LOG=n

Review URL: https://codereview.chromium.org/1337993005

Cr-Commit-Position: refs/heads/master@{#30747}

BUG=

Review URL: https://codereview.chromium.org/1343043002

Cr-Commit-Position: refs/heads/master@{#30746}

port e7fb2339 (r30710).

original commit message:

    Adds support for JS calls to the interpreter. In order to support
    calls from the interpreter, the PushArgsAndCall builtin is added
    which pushes a sequence of arguments onto the stack and calls
    builtin::Call.

    Adds the Call bytecode.

BUG=

Review URL: https://codereview.chromium.org/1334153004

Cr-Commit-Position: refs/heads/master@{#30745}

port eadfd666 (r30706).

original commit message:

    The String constructor was somewhat complex with a lot of micro
    optimizations that are not relevant or even misguided. It would be
    really hard to port that code to ES6, which requires String to be
    subclassable. So as a first step we reduced the necessary complexity
    to the bare minimum (also removing the last user of the fairly complex
    MacroAssembler::LookupNumberStringCache method).

    This also removes the counters for the String constructor, which
    were not properly exposed anymore (and not kept in sync with inlined
    versions of the String constructor anyway).

BUG=

Review URL: https://codereview.chromium.org/1336133003

Cr-Commit-Position: refs/heads/master@{#30744}

port 9fc4fc14 (r30695).

BUG=

Review URL: https://codereview.chromium.org/1339293002

Cr-Commit-Position: refs/heads/master@{#30743}

R=hpayer@chromium.org
BUG=chromium:524425
LOG=N

Review URL: https://codereview.chromium.org/1340253004

Cr-Commit-Position: refs/heads/master@{#30742}