Prevent aliasing between problematic registers for
shift operations with int64 values in the arm port
of Liftoff.

Bug: v8:6600, chromium:912592
Change-Id: I905f0a657626fdfac3e41fe2878e918e3c779a8f
Reviewed-on: https://chromium-review.googlesource.com/c/1388564
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58480}