Also added multiply low/high and vector merge instructions to
the simulator.

Change-Id: I889004b5572ee7df75be706c424ac2e83e53e8b3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2769058
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Reviewed-by: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#73492}