Return nonzero exit code if there are errors at a stop point

src/test/parse-fail/int-literal-too-large-span.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// compile-flags: -Z parse-only
+
 // issue #17123
 
 fn main() {