See: https://trac.webkit.org/changeset/232253/webkit

This is a defensive fix insofar as we were not observing any
issues, hence there is no regression test either.

Bug: v8:6791, v8:3770
Change-Id: Icdabe6a26aca9a5913fba278ae1fd0a79857dfd9
Reviewed-on: https://chromium-review.googlesource.com/1077660Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53651}