Port 2c38a477

Original Commit Message:

    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.

R=zhin@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: Ia926a4b01ed6bc9b362adce68b9301e3fc86d942
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2466625Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#70484}