The write barrier for storing a reference to an object requires the
destination offset as a parameter. The existing code only passed the
immediate offset, however, not the offset provided through a register.
With this CL, the correct offset is provided.

R=thibaudm@chromium.org

Bug: v8:7581
Change-Id: I3ab3cf41150b8f852839c1956be2fec677f68894
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2640473Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72199}