This reverts commit d368dcf4.

Reason for revert: https://crbug.com/1312188

Original change's description:
> Refactor OSROptimizedCodeCache
>
> Tweak a few names, remove a few GetIsolate calls, other minor
> usability refactors.
>
> It may be worth taking a closer look at the impl in the future,
> currently the design choices don't seem ideal (see the added TODO
> on top of the class).
>
> Bug: v8:12161
> Change-Id: Ib34e372aa58a30c68c9c5cdd0d1da0ec3e86717c
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3560447
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Jakob Linke <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#79687}

Bug: v8:12161, chromium:1312188
Change-Id: Ieb3a91682845a23536fdfdf3208af74b3c6585f8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3564989
Auto-Submit: Adam Klein <adamk@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/main@{#79700}