No longer needed.

Bug: v8:6409
Change-Id: Iea0afcb7ced24d10223db5e01f66813e97fc4134
Reviewed-on: https://chromium-review.googlesource.com/613761
Commit-Queue: Martyn Capewell <martyn.capewell@arm.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47357}