show, log: include conflict/warning messages in --remerge-diff headers

Conflicts such as modify/delete, rename/rename, or file/directory are
not representable via content conflict markers, and the normal output
messages notifying users about these were dropped with --remerge-diff.
While we don't want these messages randomly shown before the commit
and diff headers, we do want them to still be shown; include them as
part of the diff headers instead.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/merge-ort.c b/merge-ort.c
index 481305d..43f980d 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -4585,6 +4585,7 @@ static void merge_ort_nonrecursive_internal(struct merge_options *opt,
 	trace2_region_leave("merge", "process_entries", opt->repo);
 
 	/* Set return values */
+	result->path_messages = &opt->priv->output;
 	result->tree = parse_tree_indirect(&working_tree_oid);
 	/* existence of conflicted entries implies unclean */
 	result->clean &= strmap_empty(&opt->priv->conflicted);