object-file.h: move declarations for object-file.c functions from cache.h

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch-pack.c

@@ -2,6 +2,7 @@
 #include "alloc.h"
 #include "gettext.h"
 #include "hex.h"
+#include "object-file.h"
 #include "pkt-line.h"
 #include "fetch-pack.h"
 #include "remote.h"