The feature in question has been enabled by default for a while and we
no longer need to maintain a configuration without it enabled. Note that
this change only removes the mechanical pieces. Further cleanup enabled
by this will be done as follow-ups.

R=clemensh@chromium.org
BUG=v8:7549

Change-Id: I90e5bcddabe74a18a4d2a88132e8dc93317bcff4
Reviewed-on: https://chromium-review.googlesource.com/958424
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51883}