This reverts commit 42cd9eb7.

Reason for revert: Clusterfuzz issues, e.g.
https://bugs.chromium.org/p/chromium/issues/detail?id=1176318

Original change's description:
> [compiler] Directly read PropertyCells
>
> Main changes:
>
> - Introduce a new broker data kind kBackgroundSerialized for objects
>   that can be serialized in the background (when direct reads are on).
>   (I'm planning to remove kPossiblyBackgroundSerialized in a followup,
>   in favor of a dynamic choice of kSerialized or kBackgroundSerialized).
> - Make PropertyCell use that new kind.
> - Introduce a bottleneck in runtime code for changes to PropertyCells
>   and make sure that a certain protocol is followed that allows
>   concurrent reads from the background thread.
> - Improve interface of PropertyCell in various ways.
>
> Bug: v8:7790
> Change-Id: If3d7926c3b894808811348b4b2bed153f5c06897
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2661462
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72586}

TBR=ulan@chromium.org,neis@chromium.org,verwaest@chromium.org,nicohartmann@chromium.org

Change-Id: Id04145760c49fa379bc5a3fc16eba664025a9180
Bug: v8:7790
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2685125Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72619}