Port 9af9f1d0

Original commit message:
These operators compute the absolute floating point value of some
arbitrary input, and are implemented without any branches (i.e. using
vabs on arm, and andps/andpd on x86).

BUG=

Review URL: https://codereview.chromium.org/1073463003

Cr-Commit-Position: refs/heads/master@{#27679}

TEST=
BUG=

Review URL: https://codereview.chromium.org/1067393003

Cr-Commit-Position: refs/heads/master@{#27678}

Instead of "unexpected token" errors, report something meatier and more actionable.

BUG=
R=marja@chromium.org, arv@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1062263002

Cr-Commit-Position: refs/heads/master@{#27677}

BUG=v8:3754
LOG=N
R=dslomov@chromium.org, rossberg@chromium.org

Review URL: https://codereview.chromium.org/1054883003

Cr-Commit-Position: refs/heads/master@{#27676}

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

Review URL: https://codereview.chromium.org/1070843002

Cr-Commit-Position: refs/heads/master@{#27675}

BUG=chromium:452067
LOG=n

Committed: https://crrev.com/baf927ff5115ec62a6dad684b9232ed9d3960e3a
Cr-Commit-Position: refs/heads/master@{#27626}

Review URL: https://codereview.chromium.org/1045753002

Cr-Commit-Position: refs/heads/master@{#27674}

BUG=

Review URL: https://codereview.chromium.org/1069763002

Cr-Commit-Position: refs/heads/master@{#27673}

Although all this code might be moved around later, it's a good idea
to unhackify it now. :-)

Review URL: https://codereview.chromium.org/1067193004

Cr-Commit-Position: refs/heads/master@{#27672}

If we optimize a function before gathering feedback it may be
peppered with soft deoptimizations. So it can't help but deoptimize.
A judicious reading of the code isn't enough to determine what the
optimization state should be in the face of such chaotic gyrations.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/1069363003

Cr-Commit-Position: refs/heads/master@{#27671}

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

Review URL: https://codereview.chromium.org/1067413002

Cr-Commit-Position: refs/heads/master@{#27670}

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1038953002

Cr-Commit-Position: refs/heads/master@{#27669}

Because, well, JavaScript is tricky and compilers like folding.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1069673002

Cr-Commit-Position: refs/heads/master@{#27668}

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1071473003

Cr-Commit-Position: refs/heads/master@{#27667}

This allows loopy TurboFan code to be interrupted by placing a stack
check (i.e. JSStackCheck node) into each loop. Note that we currently
limit this to non-asm.js code. Also note that stack checks are actually
placed after loop headers and not at back-branches, which allows us to
reuse existing BailoutIds from Crankshaft.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/1065923002

Cr-Commit-Position: refs/heads/master@{#27666}

TEST=
BUG=

Review URL: https://codereview.chromium.org/1066403002

Cr-Commit-Position: refs/heads/master@{#27665}

Revert of VectorICs: Turn on vector ICs for LOAD and KEYED_LOAD cases. (patchset #1 id:1 of https://codereview.chromium.org/1070653002/)

Reason for revert:
ARM test failure, need to investigate.

Original issue's description:
> VectorICs: Turn on vector ICs for LOAD and KEYED_LOAD cases.
>
> R=verwaest@chromium.org
> BUG=
>
> Committed: https://crrev.com/2395eda3bb7aca938751938df76e01ac2b89b0a6
> Cr-Commit-Position: refs/heads/master@{#27657}

TBR=verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1072463002

Cr-Commit-Position: refs/heads/master@{#27664}

R=bmeurer@chromium.org
TEST=test262-es6/language/expressions/addition/S9.3_A4.1_T2

Review URL: https://codereview.chromium.org/1071543003

Cr-Commit-Position: refs/heads/master@{#27663}

These operators compute the absolute floating point value of some
arbitrary input, and are implemented without any branches (i.e. using
vabs on arm, and andps/andpd on x86).

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/1066393002

Cr-Commit-Position: refs/heads/master@{#27662}

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

Review URL: https://codereview.chromium.org/1067303003

Cr-Commit-Position: refs/heads/master@{#27661}

R=rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1071533002

Cr-Commit-Position: refs/heads/master@{#27660}

R=jarin@chromium.org
BUG=chromium:474297
LOG=N

Review URL: https://codereview.chromium.org/1062143002

Cr-Commit-Position: refs/heads/master@{#27659}

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1061303002

Cr-Commit-Position: refs/heads/master@{#27658}

R=verwaest@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1070653002

Cr-Commit-Position: refs/heads/master@{#27657}

TBR=jkummerow@chromium.org
BUG=v8:4016
LOG=N

Review URL: https://codereview.chromium.org/1071513002

Cr-Commit-Position: refs/heads/master@{#27656}

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

Review URL: https://codereview.chromium.org/1072433002

Cr-Commit-Position: refs/heads/master@{#27655}

Revert of Remove support for thread-based recompilation (patchset #1 id:1 of https://codereview.chromium.org/966653002/)

Reason for revert:
speculative revert due to gc-stress timeouts.

Original issue's description:
> Remove support for thread-based recompilation
>
> BUG=v8:3608
> R=yangguo@chromium.org
> LOG=y
>
> Committed: https://crrev.com/ed5db223a19dfe126af012e894582251aa3635d7
> Cr-Commit-Position: refs/heads/master@{#27619}

TBR=jochen@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
BUG=v8:3608
LOG=N

Review URL: https://codereview.chromium.org/1063383004

Cr-Commit-Position: refs/heads/master@{#27654}

NOTRY=true
NOTREECHECKS=true

Review URL: https://codereview.chromium.org/1064043002

Cr-Commit-Position: refs/heads/master@{#27653}

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

Review URL: https://codereview.chromium.org/1067353002

Cr-Commit-Position: refs/heads/master@{#27652}

R=yangguo@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1070663002

Cr-Commit-Position: refs/heads/master@{#27651}

Perhaps we should throw an exception and/or change our external API to
use a MaybeLocal, but that would be a bigger change. For now, we just
return undefined when something goes wrong with the DebugContext,
which is good enough to avoid crashing.

BUG=chromium:474538
LOG=y

Review URL: https://codereview.chromium.org/1065213002

Cr-Commit-Position: refs/heads/master@{#27650}

This is a follow-up to 2d281e71 and prevents bailouts on empty
script contexts in Crankshaft, which don't need allocation. Only
non-empty script contexts should cause a bailout.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1063373003

Cr-Commit-Position: refs/heads/master@{#27649}

BUG=v8:4015
LOG=n

Review URL: https://codereview.chromium.org/1040603002

Cr-Commit-Position: refs/heads/master@{#27648}

This should have been part of https://codereview.chromium.org/1056863002/. :-/

TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1070593002

Cr-Commit-Position: refs/heads/master@{#27647}

Performance measurements show that the position independent code is
usually slightly faster than the position dependent code, and there
seems to be no noticable regression.

This also gets rid of a lot of support code that was only required to allow
embedding labels into the code stream. And it implies that neither the GC
nor the deserializer need to do anything for jump tables.

R=svenpanne@chromium.org
BUG=v8:3872
LOG=n

Review URL: https://codereview.chromium.org/1069633002

Cr-Commit-Position: refs/heads/master@{#27646}

Rolling v8/tools/clang to 7ec0c52c7a66cd94c96b8eb37bacd26d152e40e6

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1070533002

Cr-Commit-Position: refs/heads/master@{#27645}

Port c67cb287

BUG=

Review URL: https://codereview.chromium.org/1061363003

Cr-Commit-Position: refs/heads/master@{#27644}

Port 2d281e71

Original commit message:
This enables eager optimization of top-level code with TurboFan and
extends test coverage by triggering it with the --always-opt flag.
Script contexts are now also properly allocated in TurboFan.

BUG=

Review URL: https://codereview.chromium.org/1066843005

Cr-Commit-Position: refs/heads/master@{#27643}

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

Review URL: https://codereview.chromium.org/1064133002

Cr-Commit-Position: refs/heads/master@{#27642}

Review URL: https://codereview.chromium.org/1067933002

Cr-Commit-Position: refs/heads/master@{#27641}

Don't create local branches or otherwise manipulate the
checkout. This reads refs from remote branches and
reads file contents using show. It is faster and requires
less bootstrapping and cleanup.

TBR=tandrii@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1060013003

Cr-Commit-Position: refs/heads/master@{#27640}