r0 is used to indicate a value of "0" in which case
only the ra() value gets used.

Change-Id: I5ea5c51c1a652d042137c2d940818b93dac52492
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3159668Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#76830}