In the case that {dst}, {lhs} and {rhs} all point to the same register,
we would emit wrong code (negating the register and adding it to
itself). This CL fixes this by checking if {lhs == rhs}, and just
clearing the {dst} register in that case.

R=thibaudm@chromium.org

Bug: chromium:1247659
Change-Id: I7913617850adb34a5ad812369f16a7422358454d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3151955Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76765}