Revert "Reland "[vm, gc] Mark through new-space.""

This reverts commit 095171e937b71acad49bb9793115f5a83ab6fff7.

Reason for revert: breaks google3 (b/296014654)

Original change's description:
> Reland "[vm, gc] Mark through new-space."
>
>  - Adjust allocation stub write barrier elimination compensation to check if result is no longer in an active TLAB.
>
> TEST=ci
> Change-Id: I5d24602ae76ee861f2d009d67272251b04da3592
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322448
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

Change-Id: I73b60f799dda755028b65653ac21f27c13e009e3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322682
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Emmanuel Pellereau <emmanuelp@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Ivan Inozemtsev <iinozemtsev@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Ivan Inozemtsev <iinozemtsev@google.com>