Cleanup StoreU64 and StoreU64WithUpdate

Change-Id: Ifaf6fd84b57b145bcbf4f2c060603adb9a08c368
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2930481Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#74897}