refs/refs-internal.h: add missing declarations (hdr-check)

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs/refs-internal.h

@@ -1,8 +1,12 @@
 #ifndef REFS_REFS_INTERNAL_H
 #define REFS_REFS_INTERNAL_H
 
+#include "cache.h"
+#include "refs.h"
 #include "iterator.h"
 
+struct ref_transaction;
+
 /*
  * Data structures and functions for the internal use of the refs
  * module. Code outside of the refs module should use only the public