This is a reland of commit 4d8e1846
One of the Mac arm64 bots failed to link an exported thread_local
static variable (crbug/1316800).

Original change's description:
> [rwx][mac] Introduce RwxMemoryWriteScope
>
> ... as a single bottleneck that encapsulates the semantics and
> implementation of fast per-thread W^X permission switching supported
> by Apple Silicon (arm64 M1).
> On other architectures this class is a no-op.
>
> Bug: v8:12797
> Change-Id: Ica842ff9f843e20b7f61fd7e80591e7a1fd29771
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3586986
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#79994}

Bug: v8:12797
Change-Id: Ifbd15c233bb343f11daa89b1328b5bf65c4806f4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3591332Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80011}