Splitting out hash table into a separate file in
b934607d caused a performance
regression.

This inlines GetHash and GetSimpleHash to fix the regression.

Bug: chromium:840694, v8:6443
Change-Id: I0466fa017a179ef2375cec4ddec8f04dfba75921
Reviewed-on: https://chromium-review.googlesource.com/1058446
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53170}