Eventually, we want to fix this also for tagged pointers (tracking bug: https://crbug.com/v8/7162).

Bug: chromium:791245
Change-Id: I93d6deff36cedcc9a4665fab0abe6fffdae9b61b
Reviewed-on: https://chromium-review.googlesource.com/806457Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49850}