X87: ES6 computed property names
X87: ES6 computed property names

port 74e38e34b3caecfb660c3ed1336a58c551215793.

original commit message:

   This adds support for computed property names, under the flag
   --harmony-computed-property-names, for both object literals and classes.

   This is a revert of the revert, 7d48fd9dc29c8f5d7c8b5215f9bd537cdd005eba.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/825593004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26090}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh