This enables fast bounds checks on FixedArray's.

Change-Id: I0ae57b2c6981d8e1b2c7017ba658fd9c890d2bad
Reviewed-on: https://chromium-review.googlesource.com/1163614
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54946}