Discovered when working on other stuff.

BUG=v8:7490,v8:8562

Change-Id: I9707c95c33e52b1565cca238494e3349a472f604
Reviewed-on: https://chromium-review.googlesource.com/c/1449532Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59276}