This will make these functions usable from Liftoff when we later
implement extended multiply instructions in Liftoff.

Bug: v8:11262
Change-Id: I5fb105bc0184675eb60cd8ae63cc13955b0f767d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2601876
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71885}