Implement vclt and add some assembler tests.

Bug: v8:10983
Change-Id: I78c701180ddc90af4b59db86a25188f281167366
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2575783
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71685}