Version 4.3.61.29 (cherry-pick)

Merged 9bf64f7e

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

R=mvstanton@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1186043002

Cr-Commit-Position: refs/branch-heads/4.3@{#34}
Cr-Branched-From: f5c0a23a-refs/heads/4.3.61@{#1}
Cr-Branched-From: 0a7d4f49-refs/heads/master@{#27508}