Only use shifts in case masking has no effects.

Change-Id: I0b8b759ce9c9689917745e81345ceb3e16e994c3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2875085Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74472}