Instead of inserting "deletion" entries into the store buffer, keep
a list of invalidated objects to filter out invalid old-to-new slots.

The first CL https://crrev.com/c/1704109 got reverted because both the sweeper and the main task were modifying the invalidated slots data structure concurrently. This CL changes this, such that the sweeper only modifies the invalidated slots during the final atomic pause when the main thread is not running. The sweeper does not need to clean this data structure after the pause, since the "update pointers" phase already removed all invalidated slots.

Bug: v8:9454
Change-Id: Iffb5bf96de2c89eee1ee1231a3414a0f2a155cbc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1733081Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63087}