upload-pack: add get_reachable_list()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/object.h b/object.h
index f8b6442..614a006 100644
--- a/object.h
+++ b/object.h
@@ -31,7 +31,7 @@
  * revision.h:      0---------10                                26
  * fetch-pack.c:    0---4
  * walker.c:        0-2
- * upload-pack.c:               11----------------19
+ * upload-pack.c:       4       11----------------19
  * builtin/blame.c:               12-13
  * bisect.c:                               16
  * bundle.c:                               16