This reverts commit d6a14abe.

Reason for revert: Caused TSAN failures.

Original change's description:
> [heap] Move start of incremental marking in allocation
> 
> Move start of incremental marking out of
> RefillLinearAllocationAreaFromFreeList. This avoids a potential
> safepoint while holding allocation_mutex_.
> 
> Bug: v8:10315
> Change-Id: Ieb60ac68f26199eea7b6b7ad6d874851382f3d69
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2287496
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68751}

TBR=ulan@chromium.org,dinfuehr@chromium.org

Change-Id: Ic928413884115ac01917a8db591af83cbbc9cc5a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2289977Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68762}