R=ahaas@chromium.org

Bug: v8:7570
Change-Id: I5327d1b8e2f2bf4c1538f565442305a0e1f05b65
Reviewed-on: https://chromium-review.googlesource.com/1032550Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52835}