Cannot verify whether slots are cleared from a concurrent sweeping task,
the OLD_TO_NEW remembered set is owned by the main thread.

Bug: v8:10562
Change-Id: I0c880f7f96350aa35b44d2966c9621576825374c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2215820
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68098}