The page flags of a large object promoted during scavenge are not
updated until the finalization of the scavenge. Thus during slots
recording they still indicate that the large object is in the from
space.

The MarkCompactCollector::RecordSlot bails out for object in young
generation, which results in missing old-to-old slot. The fix is
to insert the slot directly to the remembered set.

Bug: chromium:852420
Change-Id: Ib3d62e6d939191411729dbc2eb16b89a171a1e80
Reviewed-on: https://chromium-review.googlesource.com/c/1475765Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59646}