This improves compiler performance of the new escape analysis: runtime reduced by ~10% and zone memory reduced by ~40%.

Bug: 
Change-Id: I6b9eeaecfee6faef616d5cb8fed57fd41856898b
Reviewed-on: https://chromium-review.googlesource.com/611902
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47310}