crrev.com/2339933002 and crrev.com/2314663002 were overlapping, so
this slipped through the cracks.

R=jochen@chromium.org
BUG=v8:4947, chromium:646794

Review-Url: https://codereview.chromium.org/2343093002
Cr-Commit-Position: refs/heads/master@{#39474}