There are a couple more left in some i64x2 ops, but those are not in the
proposal, so I've left them as it is.

Bug: v8:9561
Change-Id: I3f6a4113c8054229eb6532d83ff16174a3208418
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2128849Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66990}