We need to check the KeyedLoadIC state to guard against potential
deoptimization loops due to out-of-bounds accesses, because the IC
system uses the MEGAMORPHIC state to also signal that there was an
out-of-bounds access already.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2443893002
Cr-Commit-Position: refs/heads/master@{#40525}