Remove LeftTrimFixedArray

[runtime] [ElementsAccessor] Remove LeftTrimFixedArray
Left trimming has been disabled in the GC since a while and elements.cc
is one of the few places left relying on this. Since CanMoveObjectStart
returns false by default now I am stripping away all the code relying on
it.

BUG=

[Camillo Bruni, 2015-09-08 13:16:13]

The CQ bit was checked by cbruni@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-08 13:16:18]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305353010/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305353010/1

[Camillo Bruni, 2015-09-08 13:17:01]

cbruni@chromium.org changed reviewers:
+ ulan@chromium.org

[Camillo Bruni, 2015-09-08 13:17:01]

PTAL

[ulan, 2015-09-08 13:22:13]

Is it blocking other work or is it purely cleanup?

In the latter case, I would wait until after we ship the disabled left trimming
in Chrome stable, so that we can revert easily in case of big problems in the
stable channel.

[Camillo Bruni, 2015-09-08 13:30:52]

On 2015/09/08 at 13:22:13, ulan wrote:
> Is it blocking other work or is it purely cleanup?
> 
> In the latter case, I would wait until after we ship the disabled left
trimming in Chrome stable, so that we can revert easily in case of big problems
in the stable channel.

It's purely cleanup, so I am fine with waiting :)

[commit-bot: I haz the power, 2015-09-08 13:42:08]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-08 13:42:08]

Dry run: This issue passed the CQ dry run.

[Camillo Bruni, 2015-12-04 08:52:07]

The CQ bit was checked by cbruni@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-12-04 08:52:17]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305353010/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305353010/1

[commit-bot: I haz the power, 2015-12-04 08:53:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-12-04 08:53:18]

Dry run: Try jobs failed on following builders:
  v8_linux_arm_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel/builds/11012)
  v8_linux_dbg on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg/builds/11621)
  v8_linux_mips64el_compile_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_mips64el_compile_r...)
  v8_linux_nodcheck_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_nodcheck_rel/build...)
  v8_presubmit on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/8535)

[Camillo Bruni, 2015-12-04 08:54:54]

Description was changed from

==========
Remove LeftTrimFixedArray
Left trimming has been disabled in the GC since a while and elements.cc
is one of the few places left relying on this. Since CanMoveObjectStart
returns false by default now I am stripping away all the code relying on
it.

BUG=
==========

to

==========
[runtime] [ElementsAccessor] Remove LeftTrimFixedArray
Left trimming has been disabled in the GC since a while and elements.cc
is one of the few places left relying on this. Since CanMoveObjectStart
returns false by default now I am stripping away all the code relying on
it.

BUG=
==========