These flags are no longer necessary.

Change-Id: Id686b2820ba05d7400cdb8ef9bb7f95c01cbe698
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1536451
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60416}