wrapper.h: move declarations for wrapper.c functions from cache.h

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/helper/test-delta.c

@@ -12,6 +12,7 @@
 #include "git-compat-util.h"
 #include "delta.h"
 #include "cache.h"
+#include "wrapper.h"
 
 static const char usage_str[] =
 	"test-tool delta (-d|-p) <from_file> <data_file> <out_file>";