Mimics the kArchStoreWithWriteBarrier store in generated code by having
a relaxed store to the same address, with the same value. This is done
in order for TSAN to see these stores from generated code.

Since it is done only for kArchStoreWithWriteBarrier TSAN will see
tagged stores only.

Bug: v8:7790, v8:11600

Change-Id: I275dd46f5556b3a095c416adc03f2f0ac5bde41c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2848470Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74568}