Once the escape analysis ran, it'll be harder to eliminate a bunch of
checks (for example map checks, which would currently block escape
analysis, but that's about to be fixed). Also the escape analysis will
have a lot less stress after the load elimination, which takes care of
redundant loads and checks already.

R=mstarzinger@chromium.org
BUG=v8:5448

Review-Url: https://codereview.chromium.org/2427533002
Cr-Commit-Position: refs/heads/master@{#40351}