Add David Gilbert's variadic function call support

include/ffi_common.h

@@ -75,6 +75,8 @@ void ffi_type_test(ffi_type *a, char *file, int line);
 
 /* Perform machine dependent cif processing */
 ffi_status ffi_prep_cif_machdep(ffi_cif *cif);
+ffi_status ffi_prep_cif_machdep_var(ffi_cif *cif,
+	 unsigned int nfixedargs, unsigned int ntotalargs);
 
 /* Extended cif, used in callback from assembly routine */
 typedef struct