This reverts commit cd5d72fd.

Reason for revert: breaks TSAN: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux64%20TSAN/21284

Original change's description:
> Reland "[heap] Clear from space after garbage collection.
> 
> Bug: chromium:829771
> Change-Id: I829b4d40bdbe1474eb7f087059be3e58b154768c
> Reviewed-on: https://chromium-review.googlesource.com/1106657
> Commit-Queue: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54082}

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

Change-Id: I6b719266bd088f8835d2c769d471c8872256fb40
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:829771
Reviewed-on: https://chromium-review.googlesource.com/1118298Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54086}