This reverts commit cf35926a.

Reason for revert: Speculative revert for TSAN breakage which closed the tree, e.g. https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20TSAN%20-%20stress-incremental-marking/3187/overview and https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20TSAN/36671/overview

Original change's description:
> [cleanup] Remove PropertyArray::synchronized_length_and_hash
>
> It was never stored with a release store, so can we use the loads as
> non-atomic ones.
>
> Bug: v8:7790
> Change-Id: Ife67e8650a5fb279ad808e5e68c2ab46ee3507c5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2880541
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74493}

Bug: v8:7790
Change-Id: I4f942c46631117c6573ac16ca8464c24c1c23f6e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2886886
Auto-Submit: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#74503}