This allows to have only one version of {AreAliased} which has a
clean implementation.

R=mstarzinger@chromium.org

Bug: v8:8015
Change-Id: I25c64a8c2077383129548773319799fac768521e
Reviewed-on: https://chromium-review.googlesource.com/1167290
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55007}