Optimize i64x2mul when AVX is supported to elide some moves.

Bug: v8:11589
Change-Id: Ide0bba502a35cbb632e3fc311c9697c5f54f9d82
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3163280Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76889}