This reverts commit 5cc7bfd0.

Reason for revert: Need to revert dependency.

Original change's description:
> [compiler] Clean up ObjectDataKind
>
> In particular: remove PossiblyBackgroundSerializedHeapObject in favor of
> either SerializedHeapObject or BackgroundSerializedHeapObject, depending
> on the (existing) argument to the ObjectRef constructor.
>
> Bug: v8:7790
> Change-Id: I0a67872c377107799233742cc7774bea62811d0f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2681946
> Commit-Queue: Georg Neis <neis@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72591}

TBR=neis@chromium.org,solanes@chromium.org,nicohartmann@chromium.org

Change-Id: I48a96504c29851587529d7d12cb15e569aec196b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7790
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2685124Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72617}