Also enabled concurrent linking with gold on Linux.

Mostly copy and paste from Chromium with customization for
V8 where necessary.

BUG=v8:3880
LOG=n

Review URL: https://codereview.chromium.org/896703003

Cr-Commit-Position: refs/heads/master@{#26536}

Port feb28907

Original commit message:
Adds Switch and Case operators to TurboFan and handles them
appropriately in instruction selection and code generation.

BUG=

Review URL: https://codereview.chromium.org/896973005

Cr-Commit-Position: refs/heads/master@{#26535}

Port 49cbe537

BUG=

Review URL: https://codereview.chromium.org/911623003

Cr-Commit-Position: refs/heads/master@{#26534}

   This function is defined in feb28907.
   (https://codereview.chromium.org/892513003).

   original commit message:
    [turbofan] Initial support for Switch.

    Adds Switch and Case operators to TurboFan and handles them
    appropriately in instruction selection and code generation.

BUG=

Review URL: https://codereview.chromium.org/902943005

Cr-Commit-Position: refs/heads/master@{#26533}

BUG=v8:3862
R=hpayer@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/894703002

Cr-Commit-Position: refs/heads/master@{#26532}

R=jochen@chromium.org
BUG=chromium:441896
LOG=N

Review URL: https://codereview.chromium.org/909493002

Cr-Commit-Position: refs/heads/master@{#26531}

BUG=chromium:456192
R=yangguo@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/910683002

Cr-Commit-Position: refs/heads/master@{#26530}

R=jochen@chromium.org
BUG=chromium:441896
LOG=N

Review URL: https://codereview.chromium.org/907013002

Cr-Commit-Position: refs/heads/master@{#26529}

BUG=

Review URL: https://codereview.chromium.org/907873002

Cr-Commit-Position: refs/heads/master@{#26528}

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/908863002

Cr-Commit-Position: refs/heads/master@{#26527}

port 2491a639 (r26463)

original commit message:

   Externalize deoptimization reasons.
   1) The hardcoded strings were converted into DeoptReason enum.

   2) Deopt comment were converted into a pair location and deopt reason entries so
      the deopt reason tracking mode would less affect the size of the RelocInfo table and heap.

   3) DeoptReason entry in RelocInfo reuses kCommentTag value and generates short entry in RelocInfo table.

BUG=

Review URL: https://codereview.chromium.org/867243005

Cr-Commit-Position: refs/heads/master@{#26526}

R=bmeurer@chromium.org
TEST=presubmit

Review URL: https://codereview.chromium.org/905293002

Cr-Commit-Position: refs/heads/master@{#26525}

BUG=

Review URL: https://codereview.chromium.org/910753002

Cr-Commit-Position: refs/heads/master@{#26524}

This call triggers OSR for the current function. And also allows explicitly testing OSR on the top-level code.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/906243002

Cr-Commit-Position: refs/heads/master@{#26523}

R=verwaest@chromium.org

BUG=

Review URL: https://codereview.chromium.org/906463002

Cr-Commit-Position: refs/heads/master@{#26522}

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

Review URL: https://codereview.chromium.org/898953003

Cr-Commit-Position: refs/heads/master@{#26521}

port 634b0f20 (r26454).

original commit message:

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/880743005

Cr-Commit-Position: refs/heads/master@{#26520}

port 275e088a (r26423)

original commit message:

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/907853002

Cr-Commit-Position: refs/heads/master@{#26519}

R=verwaest@chromium.org

BUG=

Review URL: https://codereview.chromium.org/904423002

Cr-Commit-Position: refs/heads/master@{#26518}

port 6fc97a19 (r26420)

original commit message:

  Retry "Use a WeakCell in the CallIC type vector."

  The first try failed because I needed to make a better distinction
  between clearing ICs according to policy at GC time or unconditional
  clearing (say, via %ClearFunctionTypeFeedback).

  It was also blocked by an issue in super constructor calls.
  This fix (https://codereview.chromium.org/892113002/) needs to land
  before checking in this CL.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/865713004

Cr-Commit-Position: refs/heads/master@{#26517}

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/911543002

Cr-Commit-Position: refs/heads/master@{#26516}

Adds Switch and Case operators to TurboFan and handles them
appropriately in instruction selection and code generation.

BUG=v8:3872
LOG=n

Review URL: https://codereview.chromium.org/892513003

Cr-Commit-Position: refs/heads/master@{#26515}

port c7851da4 (r26419)

original commit message:

  Introduce LanguageMode, drop StrictMode.

  This enables adding more language modes in the future.

  For maximum flexibility, LanguageMode is a bitmask, so we're not restricted to
  use a sequence of language modes which are progressively stricter, but we can
  express the language mode as combination of features.

  For now, LanguageMode can only be "sloppy" or "strict", and there are
  STATIC_ASSERTS in places which need to change when more modes are added.

  LanguageMode is a bit like the old LanguageMode when "extended" mode was still
  around (see https://codereview.chromium.org/8417035 and
  https://codereview.chromium.org/181543002 ) except that it's transmitted through
  all the layers (there's no StrictModeFlag).

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/902053005

Cr-Commit-Position: refs/heads/master@{#26514}

Fix build with GCC 4.6 after 158a8765.

BUG=

Review URL: https://codereview.chromium.org/908713002

Cr-Commit-Position: refs/heads/master@{#26513}

port 6f97a494 (r26409)

original commit message:

   new classes: special construct stub for derived classs and TDZ for `this`.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/902423002

Cr-Commit-Position: refs/heads/master@{#26512}

port 64f81870 (r26414)

original commit message:

  Super Constructor Calls need to use a vector slot, not an ic slot.

  The Ast Call node is accustomed to using a vector IC slot for the
  cases when it uses a CallIC. The super constructor work alters this
  somewhat by using a CallConstructStub instead, however the
  CallConstructStub expects a vector slot and not a vector ic slot.
  This distinction needs to be maintained because slots and ic slots
  have different clearing strategies and are handled differently.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/911513002

Cr-Commit-Position: refs/heads/master@{#26511}

BUG=v8:3857
LOG=N

Review URL: https://codereview.chromium.org/897543002

Cr-Commit-Position: refs/heads/master@{#26510}

TBR=marja@chromium.org

Review URL: https://codereview.chromium.org/891373003

Cr-Commit-Position: refs/heads/master@{#26509}

port 16843e23 (r26381)

original commit message:

  Megamorphic KeyedLoadIC needs special handling for vector ics.

  When --vector-ics is true, we still tail-call to the hand-written
  megamorphic KeyedLoadIC (formerly "generic"). Now that this code uses
  the megamorphic cache, it needs to deal properly with the vector and
  slot registers. Achieve this with a sentinel vectors/slot combo.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/910623002

Cr-Commit-Position: refs/heads/master@{#26508}

port c65ae4f1 (r26346).

   fix one spelling error introduced by this CL.

original commit message:
  Reland "Initial switch to Chromium-style CHECK_* and DCHECK_* macros.".

BUG=

Review URL: https://codereview.chromium.org/886833006

Cr-Commit-Position: refs/heads/master@{#26507}

port 7d363783.

original commit message:

  Continue learning for calls in crankshaft.

  The type feedback vector makes this easy to do.
  This is a re-land of https://codereview.chromium.org/868453005/
  with a fix for the DCHECK failure.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/904373002

Cr-Commit-Position: refs/heads/master@{#26506}

port 491eb817 (r26345)

BUG=

Review URL: https://codereview.chromium.org/891203003

Cr-Commit-Position: refs/heads/master@{#26505}

port 0deaa4b6 (r26340)

     (code change in full-codegen-x87.cc is covered by r26340 ).

original commit message:

   Initial switch to Chromium-style CHECK_* and DCHECK_* macros.

BUG=

Review URL: https://codereview.chromium.org/903353002

Cr-Commit-Position: refs/heads/master@{#26504}

port b18ad510 (r26291)

original commit message:

  additionally, make the interface match the JSFunction interface

BUG=

Review URL: https://codereview.chromium.org/906743002

Cr-Commit-Position: refs/heads/master@{#26503}

port 2a567faa (r26290)

original commit message:

  Use a trampoline stub to load the type feedback vector for CallICs.

BUG=

Review URL: https://codereview.chromium.org/905983002

Cr-Commit-Position: refs/heads/master@{#26502}

port c7b09aac (r26252)

original commit message:

    Along the way:
    - Thread isolate parameter explicitly through code that used to
      rely on getting it from the zone.
    - Canonicalize the parameter position of isolate and zone for
      affected code
    - Change Hydrogen New<> instruction templates to automatically
      pass isolate

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/903183003

Cr-Commit-Position: refs/heads/master@{#26501}

port 22ce08ad (r26227)
original commit message:

  new classes: change semantics of super(...) call and add new.target to construct stub.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/900423002

Cr-Commit-Position: refs/heads/master@{#26500}

Rolling v8/tools/clang to 5489bbf01a5292a6c44d4cad7875ba2cb4ac975b

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/903233003

Cr-Commit-Position: refs/heads/master@{#26499}

BUG=None
R=adamk
LOG=N

Review URL: https://codereview.chromium.org/905003003

Cr-Commit-Position: refs/heads/master@{#26498}

We incorrectly disallowed eval and arguments in accessor and method
names. This was because we checked the name inside the
ParseFunctionLiteral. We now flag accessors so that lazy parsing of
these functions are treated correctly.

BUG=v8:1984
R=adamk, dslomov@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/899363002

Cr-Commit-Position: refs/heads/master@{#26497}