The x64 side is included in https://chromium-review.googlesource.com/c/444226/

BUG=v8:5294

Change-Id: Ie255604c5e38c72e3c2b76e1ca3557a5fde108ee
Reviewed-on: https://chromium-review.googlesource.com/446394Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43481}