Add a similar check used in vlbr to make sure offset is
a 12 bit unsigned integer.

Change-Id: I12ef8734a7223fa375a31e55ecc81d1175de17c0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2977272Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75303}