Tweak test
Revert "Formalize that offset isn't recorded"

This reverts commit 65ce242021474032a28fa0f48f2d0fdee0bdb39e.

Conflicts:
	dup_key_testing/maintests.sh
	src/backend/access/nbtree/nbtinsert.c
Checkpoint progress on LWLock strengthening

This appears to work now. Haven't been able to break this.
Remove unnecessary for(;;)