Slots are always valid inside an invalidated area when outside the
respective object's current size. This allows us to remove the size
from the InvalidatedSlots data structure.

This change was enabled by https://crrev.com/c/1771793. Reland after
revert in https://crrev.com/c/1783106, this CL was not the culprit
of the issue (chromium:1000404).

Bug: v8:9454
Change-Id: I823d34670515924bf74200daa21a834044087310
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1787431Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63607}