suppress warnings about easch <applet>_main() having

no preceding prototype

coreutils/id.c

@@ -39,6 +39,7 @@ static short printf_full(unsigned int id, const char *arg, const char prefix)
 	return status;
 }
 
+int id_main(int argc, char **argv);
 int id_main(int argc, char **argv)
 {
 	struct passwd *p;