X87: Ensure object literal element boilerplates aren't modified.

X87: Ensure object literal element boilerplates aren't modified.

port 7c347c545e33d279b5aa476e754a5358201be846 (r27511)

original commit message:

    A bug allows JSObject literals with elements to have the elements in the
    boilerplate modified.

BUG=

Committed: https://crrev.com/9bf64f7e614d55766385c122a99c1e7070cd9d2b
Cr-Commit-Position: refs/heads/master@{#27595}

[chunyang.dai, 2015-04-03 02:04:54]

chunyang.dai@intel.com changed reviewers:
+ weiliang.lin@intel.com

[chunyang.dai, 2015-04-03 02:04:55]

PTAL.

[Weiliang, 2015-04-03 02:30:53]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-04-03 02:30:54]

lgtm

[commit-bot: I haz the power, 2015-04-03 02:32:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1057883004/1

[commit-bot: I haz the power, 2015-04-03 02:55:05]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-03 02:55:18]

Patchset 1 (id:??) landed as
https://crrev.com/9bf64f7e614d55766385c122a99c1e7070cd9d2b
Cr-Commit-Position: refs/heads/master@{#27595}