ll-merge: let caller decide whether to renormalize

ll-merge: let caller decide whether to renormalize

Add a “renormalize” bit to the ll-merge options word so callers can
decide on a case-by-case basis whether the merge is likely to have
overlapped with a change in smudge/clean rules.

This reveals a few commands that have not been taking that situation
into account, though it does not fix them.

No functional change intended.

Cc: Eyvind Bernhardsen <redacted>
Improved-by: Junio C Hamano <redacted>
Signed-off-by: Jonathan Nieder <redacted>
Signed-off-by: Junio C Hamano <redacted>