Reason for revert:
[Sheriff] Breaks layout tests. Please submit a needsmanualrebaseline change on the blink side for the expectations if intended.

E.g.
http://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/545

Original issue's description:
> Ship arrow functions
>
> R=rossberg@chromium.org
> LOG=Y
> BUG=v8:2700
>
> Committed: https://crrev.com/541b6c39e0ecae1c070f51fae8e9e3dab18d278c
> Cr-Commit-Position: refs/heads/master@{#29119}

TBR=rossberg@chromium.org,wingo@igalia.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:2700

Review URL: https://codereview.chromium.org/1182053013

Cr-Commit-Position: refs/heads/master@{#29125}