movXXXp are replaced with respective movXXXq.

Drive-by cleanup: unified the way we generate movq with other mov instructions.

Bug: v8:8621, v8:8562
Change-Id: I5c65dccf4e460cad5c3cee3dfabfd6ce39abc244
Reviewed-on: https://chromium-review.googlesource.com/c/1446096
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59243}