Fix to make the macro actually use the relaxed accessors instead of the
atomic ones.

Bug: v8:7790, v8:11539
Change-Id: Ic74ee4084a76176feac138716e10b88a3a5e1a1d
Fixed: v8:11539
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2748088
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73316}