After closer investigation, the crashes / regressions we currently have are not
so bad that we couldn't have the flag on.

BUG=v8:5516

Change-Id: I1b70cf99de1707d659b2e0abcd3678ec71a530bf
Reviewed-on: https://chromium-review.googlesource.com/699997Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48276}