The instruction got removed from the proposal.

R=titzer@chromium.org

Bug: v8:7581
Change-Id: I3e27bad923544896ebf6ab8969e5c365a397f6c9
Reviewed-on: https://chromium-review.googlesource.com/1128754Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54402}