revert clear-commit-marks for now.

Earlier change broke "git describe A B" among other things.
Revert it for now, and clean the commits smudged by
get_merge_bases using clear_object_marks() function.  For
complex commit ancestry graph, this is way cheaper as well.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/object.h b/object.h
index 6f23a9a180..7ac10111c6 100644
--- a/object.h
+++ b/object.h
@@ -83,4 +83,6 @@ int object_list_contains(struct object_list *list, struct object *obj);
 /* Object array handling .. */
 void add_object_array(struct object *obj, const char *name, struct object_array *array);
 
+void clear_object_marks(unsigned);
+
 #endif /* OBJECT_H */