Reason for revert:

Should be fixed after
https://chromereviews.googleplex.com/317197013/
https://codereview.chromium.org/1487413002/
https://codereview.chromium.org/1489293003/

TBR=sergiyb@chromium.org,tandrii@chromium.org
NOPRESUBMIT=true
NOTRY=true
BUG=chromium:561530

Review URL: https://codereview.chromium.org/1494103002

Cr-Commit-Position: refs/heads/master@{#32544}

  port 411c5b7f (r32524)

  original commit message:
  Also remove the ResultMode from ToBooleanStub and always return true or
  false and use the same mechanism in fullcodegen.  This is in preparation
  for adding ToBoolean hints to TurboFan.

  Drive-by-fix: We can use the power of the ToBooleanIC in TurboFan now
  that the ResultMode is gone (and the runtime always returns true or
  false from the miss handler).

BUG=

Review URL: https://codereview.chromium.org/1500483002

Cr-Commit-Position: refs/heads/master@{#32543}

Rolling v8/tools/clang to b2ed9e4af62108938543234380912eeb9d5a58e6

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

Review URL: https://codereview.chromium.org/1491363003

Cr-Commit-Position: refs/heads/master@{#32542}

BUG=v8:4588
LOG=n
TBR=yangguo@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1496863002

Cr-Commit-Position: refs/heads/master@{#32541}

  port 531dde9f (r32516)

  original commit message:
  The new step-in implementation no longer tries to predict the step-in
  target, so we don't need the arguments count nor call type anymore.

BUG=

Review URL: https://codereview.chromium.org/1493993002

Cr-Commit-Position: refs/heads/master@{#32540}

The optimized code generated by Crankshaft cannot properly deal
with proxies (in the prototype chain), and there's probably no
point in trying to make that work^Wfast with Crankshaft at all.
TurboFan will handle that properly; Crankshaft just bails out
to fullcodegen, which then goes to the runtime, which should do
the right thing soon.

BUG=v8:1543
LOG=n

Review URL: https://codereview.chromium.org/1492983002

Cr-Commit-Position: refs/heads/master@{#32539}

  port 3e7e3ed7 (r32508)

  original commit message:
  * Add a sibling interface to InterpreterAssembler called
    CodeStubAssembler which provides a wrapper around the
    RawMachineAssembler and is intented to make it easy to build
    efficient cross-platform code stubs. Much of the implementation
    of CodeStubAssembler is shamelessly stolen from the
    InterpreterAssembler, and the idea is to eventually merge the
    two interfaces somehow, probably moving the
    InterpreterAssembler interface over to use the
    CodeStubAssembler. Short-term, however, the two interfaces
    shall remain decoupled to increase our velocity developing the
    two systems in parallel.
  * Implement the StringLength stub in TurboFan with the new
    CodeStubAssembler. Replace and remove the old Hydrogen-stub
    version.
  * Remove a whole slew of machinery to support JavaScript-style
    code stub generation, since it ultimately proved unwieldy,
    brittle and baroque. This cleanup includes removing the shared
    code stub context, several example stubs and a tangle of build
    file changes.

BUG=

Review URL: https://codereview.chromium.org/1492213002

Cr-Commit-Position: refs/heads/master@{#32538}

  port 19741ac9 (r32301)

  original commit message:
  The Float32RoundTruncate operator rounds float32 numbers towards zero.
  The operator is currently implemented on x64, ia32, arm, and arm64.

  Additionally I added support for the float32 vrintz, vrintn, and vrinta
  instructions to the arm simulator.

BUG=

Review URL: https://codereview.chromium.org/1493213002

Cr-Commit-Position: refs/heads/master@{#32537}

Both the is_const and declaration_scope fields can be reliably derived
from the mode field. needs_init cannot be, unfortunately, due to the
special case of CONST in for loops.

Also inline the sole remaining non-trivial caller of
Parser::DeclarationScope(VariableMode).

Review URL: https://codereview.chromium.org/1487603003

Cr-Commit-Position: refs/heads/master@{#32536}

Review URL: https://codereview.chromium.org/1485823003

Cr-Commit-Position: refs/heads/master@{#32535}

These bits were relevant back when we had nested lexical modules, but
I don't think they'll be of any use for ES2015 modules.

Review URL: https://codereview.chromium.org/1485053002

Cr-Commit-Position: refs/heads/master@{#32534}

Port 531dde9f

Original commit message:
    The new step-in implementation no longer tries to predict the step-in
    target, so we don't need the arguments count nor call type anymore.

R=yangguo@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1490413002

Cr-Commit-Position: refs/heads/master@{#32533}

Port 3e7e3ed7

Original commit message:
    * Add a sibling interface to InterpreterAssembler called
      CodeStubAssembler which provides a wrapper around the
      RawMachineAssembler and is intented to make it easy to build
      efficient cross-platform code stubs. Much of the implementation
      of CodeStubAssembler is shamelessly stolen from the
      InterpreterAssembler, and the idea is to eventually merge the
      two interfaces somehow, probably moving the
      InterpreterAssembler interface over to use the
      CodeStubAssembler. Short-term, however, the two interfaces
      shall remain decoupled to increase our velocity developing the
      two systems in parallel.
    * Implement the StringLength stub in TurboFan with the new
      CodeStubAssembler. Replace and remove the old Hydrogen-stub
      version.
    * Remove a whole slew of machinery to support JavaScript-style
      code stub generation, since it ultimately proved unwieldy,
      brittle and baroque. This cleanup includes removing the shared
      code stub context, several example stubs and a tangle of build
      file changes.

R=danno@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4587
LOG=n

Review URL: https://codereview.chromium.org/1492633006

Cr-Commit-Position: refs/heads/master@{#32532}

Port 411c5b7f

Original commit message:
    Also remove the ResultMode from ToBooleanStub and always return true or
    false and use the same mechanism in fullcodegen.  This is in preparation
    for adding ToBoolean hints to TurboFan.

    Drive-by-fix: We can use the power of the ToBooleanIC in TurboFan now
    that the ResultMode is gone (and the runtime always returns true or
    false from the miss handler).

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4583
LOG=n

Review URL: https://codereview.chromium.org/1490363003

Cr-Commit-Position: refs/heads/master@{#32531}

Revert of Disable non-standard Promise functions in staging (patchset #1 id:1 of https://codereview.chromium.org/1478533002/ )

Reason for revert:
Will test better; there seems to be a bug related to this.

Original issue's description:
> Reland of Disable non-standard Promise functions in staging (patchset #1 id:1 of https://codereview.chromium.org/1473603002/ )
>
> Reason for revert:
> Breakage in Ignition seems unrelated; relanding.
>
> Original issue's description:
> > Revert of Disable non-standard Promise functions in staging (patchset #5 id:80001 of https://codereview.chromium.org/1469543003/ )
> >
> > Reason for revert:
> > [Sheriff] This breaks ignition on arm sim debug:
> > https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/builds/5317
> >
> > Seems to not be caught by the cq bot that builds release with dchecks.
> >
> > Original issue's description:
> > > Disable non-standard Promise functions in staging
> > >
> > > This patch removes Promise functions and methods which are absent
> > > from the ES2015 specification when the --es-staging flag is on.
> > >
> > > BUG=v8:3237
> > > R=rossberg
> > > LOG=Y
> > >
> > > Committed: https://crrev.com/941251af7e04d50ac2243da2870249a42111221a
> > > Cr-Commit-Position: refs/heads/master@{#32194}
> >
> > TBR=rossberg@chromium.org,littledan@chromium.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=v8:3237
> >
> > Committed: https://crrev.com/86bd2b3c23b562213d5af158849dcd65f347a827
> > Cr-Commit-Position: refs/heads/master@{#32199}
>
> TBR=rossberg@chromium.org,rmcilroy@chromium.org,machenbach@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:3237
>
> Committed: https://crrev.com/9278b7b05a45c2089007e8b61822af96b5d0c8df
> Cr-Commit-Position: refs/heads/master@{#32235}

TBR=rossberg@chromium.org,rmcilroy@chromium.org,machenbach@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3237

Review URL: https://codereview.chromium.org/1493713004

Cr-Commit-Position: refs/heads/master@{#32530}

update.sh is gone in chromium, and using update.py will do the right
thing both before and after the deletion in chromium (previously,
update.py used to call update.sh internally on non-win).

This also has the benefit of working on Windows.

No intended behavior change.

BUG=chromium:494442
LOG=n

Review URL: https://codereview.chromium.org/1495653002

Cr-Commit-Position: refs/heads/master@{#32529}

LOG=Y
BUG=chromium:558998
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1495633002

Cr-Commit-Position: refs/heads/master@{#32528}

This hackily disambiguates multiple calls for the iterator protocols in ForOf / Yield* by adding -2 / -1 to the pos.

BUG=v8:3953
LOG=y

Review URL: https://codereview.chromium.org/1491923003

Cr-Commit-Position: refs/heads/master@{#32527}

While execution will not return to this location, stack iteration
logic will attempt to find the code object associated with the return
address.  This makes sure that it maps to the correct object and not
to the one immediately following it in memory.

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1490343002

Cr-Commit-Position: refs/heads/master@{#32526}

Split out of PropertyAttributes, and used for all filtering purposes.
Also moved PropertyAttributes into the v8::internal:: namespace.

No change in behavior intended.

Review URL: https://codereview.chromium.org/1492653004

Cr-Commit-Position: refs/heads/master@{#32525}

Also remove the ResultMode from ToBooleanStub and always return true or
false and use the same mechanism in fullcodegen.  This is in preparation
for adding ToBoolean hints to TurboFan.

Drive-by-fix: We can use the power of the ToBooleanIC in TurboFan now
that the ResultMode is gone (and the runtime always returns true or
false from the miss handler).

R=mstarzinger@chromium.org
BUG=v8:4583
LOG=n

Review URL: https://codereview.chromium.org/1491223002

Cr-Commit-Position: refs/heads/master@{#32524}

R=mstarzinger@chromium.org
BUG=v8:4586
LOG=n

Review URL: https://codereview.chromium.org/1491903002

Cr-Commit-Position: refs/heads/master@{#32523}

Revert of [heap] Refactor evacuation for young and old gen into visitors. (patchset #1 id:1 of https://codereview.chromium.org/1493523003/ )

Reason for revert:
Speculative revert for crashing Canary.

Original issue's description:
> Reland of [heap] Refactor evacuation for young and old gen into visitors. (patchset #1 id:1 of https://codereview.chromium.org/1483393002/ )
>
> Reason for revert:
> Reland after fixing the potential root cause of the canary crasher.
>
> Original issue's description:
> > Revert of [heap] Refactor evacuation for young and old gen into visitors. (patchset #5 id:80001 of https://codereview.chromium.org/1470253002/ )
> >
> > Reason for revert:
> > Still investigating bad canary.
> >
> > Original issue's description:
> > > [heap] Refactor evacuation for young and old gen into visitors.
> > >
> > > Create a visitor for evacuating objects for young and old generation. This is
> > > the first step of preparing a task to process, both,  newspace and oldspace
> > > pages in parallel.
> > >
> > > BUG=chromium:524425
> > > LOG=N
> > >
> > > Committed: https://crrev.com/138d9bae5d7014e0d205634a49b5eac3697744c8
> > > Cr-Commit-Position: refs/heads/master@{#32349}
> >
> > TBR=mlippautz@chromium.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=chromium:524425
> >
> > Committed: https://crrev.com/aa24a3135ec308e1f84bce334844caf0cae2437a
> > Cr-Commit-Position: refs/heads/master@{#32462}
>
> TBR=mlippautz@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:524425
>
> Committed: https://crrev.com/120b640dfce5f02cecc5af72ca0b2b3b93ce8652
> Cr-Commit-Position: refs/heads/master@{#32500}

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

Review URL: https://codereview.chromium.org/1495583002

Cr-Commit-Position: refs/heads/master@{#32522}

Revert of [heap] Unify evacuating an object for new and old generation. (patchset #1 id:1 of https://codereview.chromium.org/1494533002/ )

Reason for revert:
Speculative revert for crashing Canary.

Original issue's description:
> Reland of [heap] Unify evacuating an object for new and old generation. (patchset #1 id:1 of https://codereview.chromium.org/1483963004/ )
>
> Reason for revert:
> Reland after fixing the potential root cause of the canary crasher.
>
> Original issue's description:
> > Revert of [heap] Unify evacuating an object for new and old generation. (patchset #2 id:20001 of https://codereview.chromium.org/1481873002/ )
> >
> > Reason for revert:
> > Still investigating bad canary.
> >
> > Original issue's description:
> > > [heap] Unify evacuating an object for new and old generation.
> > >
> > > BUG=chromium:524425
> > > LOG=N
> > >
> > > Committed: https://crrev.com/afb8bcce8ba889280ed747eb218d287ddd233b4a
> > > Cr-Commit-Position: refs/heads/master@{#32365}
> >
> > TBR=mlippautz@chromium.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=chromium:524425
> >
> > Committed: https://crrev.com/9c60ddc60e96da0c59e646660789c26550ad52a2
> > Cr-Commit-Position: refs/heads/master@{#32460}
>
> TBR=mlippautz@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:524425
>
> Committed: https://crrev.com/7ea8ac98f6eb5ffa9d4976aa22fec9befb814e0c
> Cr-Commit-Position: refs/heads/master@{#32501}

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

Review URL: https://codereview.chromium.org/1491013003

Cr-Commit-Position: refs/heads/master@{#32521}

Revert of "[heap] Clean up stale store buffer entries for aborted pages." (patchset #3 id:40001 of https://codereview.chromium.org/1494503004/ )

Reason for revert:
Still failing on GC stress
  https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux%20-%20gc%20stress/builds/690

Original issue's description:
> Reland of "[heap] Clean up stale store buffer entries for aborted pages."
>
> This reverts commit d4fc4a8c.
>
> 1.  Let X be the aborted slot (slot in an evacuated object in an aborted page)
> 2.  Assume X contains pointer to Y and Y is in the new space, so X is in the
>     store buffer.
> 3.  Store buffer rebuilding will not filter out X (it checks InNewSpace(Y)).
> 4.  The current mark-sweep finishes. The slot X is in free space and is also in
>     the store buffer.
> 5.  A string of length 9 "abcdefghi" is allocated in the new space. The string
>     looks like |MAP|LENGTH|hgfedcba|NNNNNNNi| in memory, where NNNNNNN is
>     previous garbage. Let's assume that NNNNNNN0 was pointing to a new space
>     object before.
> 6.  Scavenge happens.
> 7.  Slot X is still in free space and in store buffer. [It causes scavenge of
>     the object Y in
>     store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject). But
>     it is not important].
> 8.  Our string is promoted and is allocated over the slot X, such that NNNNNNNi
>     is written in X.
> 9.  The scavenge finishes.
> 9.  Another scavenge starts.
> 10. We crash in
>     store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject) when
>     processing slot X, because it doesn't point to valid map.
>
> BUG=chromium:524425, chromium:564498
> LOG=N
> R=hpayer@chromium.org, ulan@chromium.org
>
> Committed: https://crrev.com/fc6ff534003480e49dc481d9c665e961ab709c02
> Cr-Commit-Position: refs/heads/master@{#32514}

TBR=hpayer@chromium.org,ulan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:524425, chromium:564498

Review URL: https://codereview.chromium.org/1492823002

Cr-Commit-Position: refs/heads/master@{#32520}

We can constant fold %_IsJSReceiver(x) based on whether x is always a
receiver or can never be a receiver.  This is important as
%_IsJSReceiver is inserted by the JSInliner.

R=jarin@chromium.org
BUG=v8:4544
LOG=n

Review URL: https://codereview.chromium.org/1486383003

Cr-Commit-Position: refs/heads/master@{#32519}

R=mvstanton@chromium.org, yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1491683003

Cr-Commit-Position: refs/heads/master@{#32518}

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/1493733002

Cr-Commit-Position: refs/heads/master@{#32517}

The new step-in implementation no longer tries to predict the step-in
target, so we don't need the arguments count nor call type anymore.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/1484893003

Cr-Commit-Position: refs/heads/master@{#32516}

  port 4f494789 (r32262)

  original commit message:
  The Float32RoundUp operator rounds float32 numbers towards infinity.
  The operator is currently implemented on x64, ia32, arm, and arm64.

BUG=

Review URL: https://codereview.chromium.org/1491843003

Cr-Commit-Position: refs/heads/master@{#32515}

This reverts commit d4fc4a8c.

1.  Let X be the aborted slot (slot in an evacuated object in an aborted page)
2.  Assume X contains pointer to Y and Y is in the new space, so X is in the
    store buffer.
3.  Store buffer rebuilding will not filter out X (it checks InNewSpace(Y)).
4.  The current mark-sweep finishes. The slot X is in free space and is also in
    the store buffer.
5.  A string of length 9 "abcdefghi" is allocated in the new space. The string
    looks like |MAP|LENGTH|hgfedcba|NNNNNNNi| in memory, where NNNNNNN is
    previous garbage. Let's assume that NNNNNNN0 was pointing to a new space
    object before.
6.  Scavenge happens.
7.  Slot X is still in free space and in store buffer. [It causes scavenge of
    the object Y in
    store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject). But
    it is not important].
8.  Our string is promoted and is allocated over the slot X, such that NNNNNNNi
    is written in X.
9.  The scavenge finishes.
9.  Another scavenge starts.
10. We crash in
    store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject) when
    processing slot X, because it doesn't point to valid map.

BUG=chromium:524425, chromium:564498
LOG=N
R=hpayer@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/1494503004

Cr-Commit-Position: refs/heads/master@{#32514}

BUG=

Review URL: https://codereview.chromium.org/1491613002

Cr-Commit-Position: refs/heads/master@{#32513}

Revert of [CQ] Update proto format to fix triggered builders. (patchset #1 id:1 of https://codereview.chromium.org/1495443003/ )

Reason for revert:
Still not working

Original issue's description:
> Reland of [CQ] Update proto format to fix triggered builders. (patchset #1 id:1 of https://codereview.chromium.org/1485813004/ )
>
> Reason for revert:
> Should be fixed after https://codereview.chromium.org/1487413002/
>
> Original issue's description:
> > Revert of [CQ] Update proto format to fix triggered builders. (patchset #1 id:1 of https://codereview.chromium.org/1486963002/ )
> >
> > Reason for revert:
> > Maybe causing problems
> >
> > Original issue's description:
> > > [CQ] Update proto format to fix triggered builders.
> > >
> > > Depends on https://chromereviews.googleplex.com/319777013/
> > >
> > > BUG=chromium:561530
> > > LOG=n
> > > TBR=sergiyb@chromium.org, tandrii@chromium.org
> > > NOTRY=true
> > >
> > > Committed: https://crrev.com/51d6d619330080a76c5bc7a2ebdafebc6a808aa8
> > > Cr-Commit-Position: refs/heads/master@{#32453}
> >
> > TBR=sergiyb@chromium.org,tandrii@chromium.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=chromium:561530
> >
> > Committed: https://crrev.com/79ded5acc9da6a80cbd739c24c6dfa0cf207ae93
> > Cr-Commit-Position: refs/heads/master@{#32464}
>
> TBR=sergiyb@chromium.org,tandrii@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:561530
>
> Committed: https://crrev.com/3cea13351c1af365013f51c7b67e72eeba79afe6
> Cr-Commit-Position: refs/heads/master@{#32511}

TBR=sergiyb@chromium.org,tandrii@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:561530

Review URL: https://codereview.chromium.org/1493693003

Cr-Commit-Position: refs/heads/master@{#32512}

Reland of [CQ] Update proto format to fix triggered builders. (patchset #1 id:1 of https://codereview.chromium.org/1485813004/ )

Reason for revert:
Should be fixed after https://codereview.chromium.org/1487413002/

Original issue's description:
> Revert of [CQ] Update proto format to fix triggered builders. (patchset #1 id:1 of https://codereview.chromium.org/1486963002/ )
>
> Reason for revert:
> Maybe causing problems
>
> Original issue's description:
> > [CQ] Update proto format to fix triggered builders.
> >
> > Depends on https://chromereviews.googleplex.com/319777013/
> >
> > BUG=chromium:561530
> > LOG=n
> > TBR=sergiyb@chromium.org, tandrii@chromium.org
> > NOTRY=true
> >
> > Committed: https://crrev.com/51d6d619330080a76c5bc7a2ebdafebc6a808aa8
> > Cr-Commit-Position: refs/heads/master@{#32453}
>
> TBR=sergiyb@chromium.org,tandrii@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:561530
>
> Committed: https://crrev.com/79ded5acc9da6a80cbd739c24c6dfa0cf207ae93
> Cr-Commit-Position: refs/heads/master@{#32464}

TBR=sergiyb@chromium.org,tandrii@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:561530

Review URL: https://codereview.chromium.org/1495443003

Cr-Commit-Position: refs/heads/master@{#32511}

NOTRY=true
TBR=hpayer@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/1490263002

Cr-Commit-Position: refs/heads/master@{#32510}

BUG=v8:2487
LOG=n
R=vogelheim@chromium.org

Review URL: https://codereview.chromium.org/1496493002

Cr-Commit-Position: refs/heads/master@{#32509}

* Add a sibling interface to InterpreterAssembler called
  CodeStubAssembler which provides a wrapper around the
  RawMachineAssembler and is intented to make it easy to build
  efficient cross-platform code stubs. Much of the implementation
  of CodeStubAssembler is shamelessly stolen from the
  InterpreterAssembler, and the idea is to eventually merge the
  two interfaces somehow, probably moving the
  InterpreterAssembler interface over to use the
  CodeStubAssembler. Short-term, however, the two interfaces
  shall remain decoupled to increase our velocity developing the
  two systems in parallel.
* Implement the StringLength stub in TurboFan with the new
  CodeStubAssembler. Replace and remove the old Hydrogen-stub
  version.
* Remove a whole slew of machinery to support JavaScript-style
  code stub generation, since it ultimately proved unwieldy,
  brittle and baroque. This cleanup includes removing the shared
  code stub context, several example stubs and a tangle of build
  file changes.

BUG=v8:4587
LOG=n

Review URL: https://codereview.chromium.org/1475953002

Cr-Commit-Position: refs/heads/master@{#32508}

The main part of the Proxy constructor was already in C++, there's
actually no point in keeping a JavaScript wrapper.

R=cbruni@chromium.org
BUG=v8:1543
LOG=n

Review URL: https://codereview.chromium.org/1491893002

Cr-Commit-Position: refs/heads/master@{#32507}

BUG=

Review URL: https://codereview.chromium.org/1484393002

Cr-Commit-Position: refs/heads/master@{#32506}

Allow to pass new.target (in addition to target) to C++ builtins, and
remove some obsolete/dangerous code from the C++ builtins.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1491883002

Cr-Commit-Position: refs/heads/master@{#32505}