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 <eyvind.bernhardsen@gmail.com>
Improved-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -150,6 +150,10 @@ static int checkout_merged(int pos, struct checkout *state)
 	read_mmblob(&ours, active_cache[pos+1]->sha1);
 	read_mmblob(&theirs, active_cache[pos+2]->sha1);
 
+	/*
+	 * NEEDSWORK: re-create conflicts from merges with
+	 * merge.renormalize set, too
+	 */
 	status = ll_merge(&result_buf, path, &ancestor, "base",
 			  &ours, "ours", &theirs, "theirs", 0);
 	free(ancestor.ptr);