Remove dead code on the way.

Bug: v8:6474
Change-Id: I7edb4277bc53ee92edf9523b943492782ec6efac
Reviewed-on: https://chromium-review.googlesource.com/538652Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45976}