These instructions are not in the proposal, and will be unlikely to be
requested (poor performance, insufficient use cases). As we get more
instruction suggestions, these are sitting around on useful opcodes and
we have to play musical chairs every time we prototype a new
instruction.

Bug: v8:10933
Change-Id: Ic7ce4e514c343d821f76b8c071e41f9bddfbd1ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2457669Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70455}