When concurrent marking is on then normal stores to tagged fields must
be relaxed stores.

Bug: v8:9396
Change-Id: Id1189a6c7df5ae8e9e5dc4dad653d35bdd109c5e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1677207Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62378}