compat: Add simplified merge sort implementation from glibc

diff --git a/builtin-show-ref.c b/builtin-show-ref.c
index 9463ff0e69b15fc0e544259e64960bc942a98368..65051d14fde44c14d12099df656ac423bc1c347e 100644 (file)
--- a/builtin-show-ref.c
+++ b/builtin-show-ref.c
@@ -1,3 +1,4 @@
+#include "builtin.h"
 #include "cache.h"
 #include "refs.h"
 #include "object.h"