PPC: [for-in] Sanitize for-in optimizations and fix bailout points.

PPC: [for-in] Sanitize for-in optimizations and fix bailout points.

Port f48bf12f5ea99a9d01d390c0c7f51dc85a87f1cd

Original commit message:
    The PrepareId bailout location was used incorrectly in Crankshaft and,
    as it turns out, is not required anyway (once you do it right). Also
    there was some premature optimization going on with the CheckEnumCache
    (trying to load null from roots only once), plus we can be smarter about
    the null/undefined check anyway.

    The idea behind this changes is to prepare unification of the two
    different ForInPrepare implementations that we now have, with the end
    result being that we only use the new implementation that was recently
    added for the interpreter.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:3650
LOG=n

Committed: https://crrev.com/cbc0564037991a69975edb0e3fdc33df9cf472c0
Cr-Commit-Position: refs/heads/master@{#33447}

[MTBrandyberry, 2016-01-21 17:56:29]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2016-01-21 17:56:31]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1619643004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1619643004/1

[commit-bot: I haz the power, 2016-01-21 18:18:26]

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

[commit-bot: I haz the power, 2016-01-21 18:18:26]

Dry run: This issue passed the CQ dry run.

[john.yan, 2016-01-21 19:07:17]

lgtm

[MTBrandyberry, 2016-01-21 19:12:52]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2016-01-21 19:12:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1619643004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1619643004/1

[commit-bot: I haz the power, 2016-01-21 19:14:51]

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

[commit-bot: I haz the power, 2016-01-21 19:14:54]

Try jobs failed on following builders:
  v8_presubmit on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/10026)

[MTBrandyberry, 2016-01-21 19:20:52]

The CQ bit was checked by mbrandy@us.ibm.com

[MTBrandyberry, 2016-01-21 19:20:53]

The patchset sent to the CQ was uploaded after l-g-t-m from jyan@ca.ibm.com
Link to the patchset: https://codereview.chromium.org/1619643004/#ps20001
(title: "Rebase")

[commit-bot: I haz the power, 2016-01-21 19:20:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1619643004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1619643004/20001

[commit-bot: I haz the power, 2016-01-21 19:45:59]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-21 19:46:28]

Description was changed from

==========
PPC: [for-in] Sanitize for-in optimizations and fix bailout points.

Port f48bf12f5ea99a9d01d390c0c7f51dc85a87f1cd

Original commit message:
    The PrepareId bailout location was used incorrectly in Crankshaft and,
    as it turns out, is not required anyway (once you do it right). Also
    there was some premature optimization going on with the CheckEnumCache
    (trying to load null from roots only once), plus we can be smarter about
    the null/undefined check anyway.

    The idea behind this changes is to prepare unification of the two
    different ForInPrepare implementations that we now have, with the end
    result being that we only use the new implementation that was recently
    added for the interpreter.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=v8:3650
LOG=n
==========

to

==========
PPC: [for-in] Sanitize for-in optimizations and fix bailout points.

Port f48bf12f5ea99a9d01d390c0c7f51dc85a87f1cd

Original commit message:
    The PrepareId bailout location was used incorrectly in Crankshaft and,
    as it turns out, is not required anyway (once you do it right). Also
    there was some premature optimization going on with the CheckEnumCache
    (trying to load null from roots only once), plus we can be smarter about
    the null/undefined check anyway.

    The idea behind this changes is to prepare unification of the two
    different ForInPrepare implementations that we now have, with the end
    result being that we only use the new implementation that was recently
    added for the interpreter.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=v8:3650
LOG=n

Committed: https://crrev.com/cbc0564037991a69975edb0e3fdc33df9cf472c0
Cr-Commit-Position: refs/heads/master@{#33447}
==========

[commit-bot: I haz the power, 2016-01-21 19:46:29]

Patchset 2 (id:??) landed as
https://crrev.com/cbc0564037991a69975edb0e3fdc33df9cf472c0
Cr-Commit-Position: refs/heads/master@{#33447}