If the immediate is a 32-bit value, we can just write the lower half of
the target register, the upper half will automatically be zero-extended.

R=tebbi@chromium.org

Bug: v8:10005
Change-Id: Ib3c54c9f6ac2434c7345c507529298233d6b7d6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3563565Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79758}