This reverts commit 0a661a9a.

Reason for revert: 4683d6fe broke TSAN, reverting all its dependencies first (including this)
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20TSAN/36744/overview



Original change's description:
> Revert "[compiler] Temporarily change ContextRef back to kSerialized"
>
> This reverts commit 445f0f74.
>
> Reason for revert: TryMakeRef is again ready for this.
>
> Original change's description:
> > [compiler] Temporarily change ContextRef back to kSerialized
> >
> > This can be reverted once TryMakeRef checks the heap predicate.
> > I'm not reverting the previous CL because newer changes already depend
> > on it.
> >
> > Tbr: jgruber@chromium.org
> > Bug: v8:11765, v8:7790
> > Change-Id: Iacc6a78a70fe6f40c9421258889c2175fb400b04
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2891579
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Commit-Queue: Georg Neis <neis@chromium.org>
> > Auto-Submit: Georg Neis <neis@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#74531}
>
> Bug: v8:11765
> Bug: v8:7790
> Change-Id: I0b38791255182f1f8d0a5cf79f18d86568172487
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2897101
> Commit-Queue: Georg Neis <neis@chromium.org>
> Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Auto-Submit: Georg Neis <neis@chromium.org>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74591}

Bug: v8:11765
Bug: v8:7790
Change-Id: I462b9b098781101549ebd6c185697d4b235c2888
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2901989
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74620}