Codegen is identical to x64.

Tweaked a macro definition to do a dst == src1 check when AVX is not
supported, and updated a single caller in LiftOff.

Bug: v8:11086
Change-Id: Ic9645f3d1bf1c26a1aa6db6bc2fa67fc991f8bbb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2579928
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71756}