.. when concurrent inlining is on.

SerializeBackPointer
SerializeForElementLoad
SerializeRootMap

For SerializeRootMap: Due to changed root map access timing, it
is now possible to see an abandoned prototype map - added logic
for that in RemoveImpossibleMaps.

Bug: v8:7790
Change-Id: Icdb3fff12536bfdc84923e7cd40bad9978a2a401
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2948658
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75065}