Make `RegExp.prototype.flags` getter configurable

TEST=mjsunit/harmony
BUG=v8:3751
LOG=N

Review URL: https://codereview.chromium.org/788053003

Cr-Commit-Position: refs/heads/master@{#25809}
Use C++11 nullptr in Hydrogen to replace static_cast<HValue*>(NULL)

Review URL: https://codereview.chromium.org/805523002

Cr-Commit-Position: refs/heads/master@{#25810}
[turbofan] Remove obsolete contains_js_nodes_ field.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/806653003

Cr-Commit-Position: refs/heads/master@{#25811}
[turbofan] Correctify TruncateFloat64ToInt32 reduction in MachineOperatorReducer.

TEST=unittests
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/801263002

Cr-Commit-Position: refs/heads/master@{#25812}
Call DisableInlineAllocation() in heap setup when flag inline_new is off.

BUG=

Review URL: https://codereview.chromium.org/790353006

Cr-Commit-Position: refs/heads/master@{#25813}
[turbofan] Remove the no-context hack for JSToNumber.

The ToNumberStub is now able to handle all plain primitives (Numbers,
Booleans, Null, Undefined and Strings) without context access.

TEST=cctest,mjsunit,unittests

Review URL: https://codereview.chromium.org/801333002

Cr-Commit-Position: refs/heads/master@{#25814}
Revert of Call DisableInlineAllocation() in heap setup when flag inline_new is off. (patchset #1 id:1 of https://codereview.chromium.org/790353006/)

Reason for revert:
Fix Windows nosnap.

Original issue's description:
> Call DisableInlineAllocation() in heap setup when flag inline_new is off.
>
> BUG=

TBR=ulan@chromium.org,mstarzinger@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/794053003

Cr-Commit-Position: refs/heads/master@{#25815}
LayoutDescriptorHelper is now able to calculate the length of contiguous regions of tagged/non-tagged fields.
This functionality is now used by both object visitor and store buffer.

TEST=cctest/test-unboxed-doubles

Review URL: https://codereview.chromium.org/726713003

Cr-Commit-Position: refs/heads/master@{#25816}
Hydrogen: fix keyed loads with string keys

Keyed loads should not unconditionally be compiled to element loads. Update KeyedLoadICs to keep track of the key type, so that Hydrogen can emit ICs for string-keyed loads it doesn't have inline support for.

BUG=v8:3167
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/755513003

Cr-Commit-Position: refs/heads/master@{#25817}
[turbofan] Relax effects and context for JSToNumber(x:plain-primitive).

TEST=unittests
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/799413002

Cr-Commit-Position: refs/heads/master@{#25818}
Reland Call DisableInlineAllocation() in heap setup when flag inline_new is off.

BUG=

Review URL: https://codereview.chromium.org/806783002

Cr-Commit-Position: refs/heads/master@{#25819}
Take the build level into account for the version hash

build is the third number of the V8 version, and very likely to change
(in contrast to the patch level which typically is zero on canaries).

BUG=chromium:440984
R=mvstanton@chromium.org,yangguo@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/802363002

Cr-Commit-Position: refs/heads/master@{#25820}
ES6 computed property names

This adds support for computed property names, under the flag
--harmony-computed-property-names, for both object literals and
classes.

BUG=v8:3754
LOG=Y

Review URL: https://codereview.chromium.org/795573005

Cr-Commit-Position: refs/heads/master@{#25821}
Internalize strings being stored into uninitialized property cells

Review URL: https://codereview.chromium.org/804993002

Cr-Commit-Position: refs/heads/master@{#25822}
Add fast path for array indices to Runtime_HasOwnProperty

Review URL: https://codereview.chromium.org/803833004

Cr-Commit-Position: refs/heads/master@{#25823}
MIPS: [turbofan] Remove the no-context hack for JSToNumber.

Port d211608a3eb7ef3da4d04fd4f5a8540dedbd1faa

Original commit message:
The ToNumberStub is now able to handle all plain primitives (Numbers,
Booleans, Null, Undefined and Strings) without context access.

TEST=cctest,mjsunit,unittests
BUG=

Review URL: https://codereview.chromium.org/803973002

Cr-Commit-Position: refs/heads/master@{#25824}
Revert of ES6 computed property names (patchset #9 id:160001 of https://codereview.chromium.org/795573005/)

Reason for revert:
Crashes on Win32

http://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%201/builds/1357

Test: mjsunit/harmony/computed-property-names
Flags: --stress-opt --always-opt
Command: build\Release\d8.exe --test --random-seed=-233815021 --stress-opt --always-opt --nohard-abort --nodead-code-elimination --nofold-constants --harmony-computed-property-names test\mjsunit\mjsunit.js test\mjsunit\harmony\computed-property-names.js

Run #1
Exit code: -1073741819
Result: CRASH
Expected outcomes: PASS

Run #2
Exit code: -1073741819
Result: CRASH
Expected outcomes: PASS

Run #3
Exit code: -1073741819
Result: CRASH
Expected outcomes: PASS

Original issue's description:
> ES6 computed property names
>
> This adds support for computed property names, under the flag
> --harmony-computed-property-names, for both object literals and
> classes.
>
> BUG=v8:3754
> LOG=Y

TBR=dslomov@chromium.org,wingo@igalia.com
NOTREECHECKS=true
NOTRY=true
BUG=v8:3754

Review URL: https://codereview.chromium.org/809433002

Cr-Commit-Position: refs/heads/master@{#25825}
Ship ES6 classes.

R=arv@chromium.org
BUG=v8:3330
LOG=Y

Review URL: https://codereview.chromium.org/808433002

Cr-Commit-Position: refs/heads/master@{#25826}
[GN] Output external snapshot blobs in out directory.

The snapshot and natives blob files should be output in the out directory
instead of the gen directory so that they can be picked up by the
executable.

BUG=421063
LOG=N

Review URL: https://codereview.chromium.org/805813004

Cr-Commit-Position: refs/heads/master@{#25827}
Use proper ToLength() operation in %ArrayConcat()

LOG=N
R=dslomov@chromium.org
BUG=

Review URL: https://codereview.chromium.org/799853003

Cr-Commit-Position: refs/heads/master@{#25828}