make test pass even though the span makes no sense

tests/compile-fail/erroneous_const.rs

@@ -2,16 +2,16 @@
 //! (https://github.com/rust-lang/miri/issues/1382)
 #![feature(const_panic)]
 #![feature(never_type)]
-#![warn(const_err)]
+#![warn(warnings, const_err)]
 
 struct PrintName<T>(T);
 impl<T> PrintName<T> {
     const VOID: ! = panic!(); //~WARN any use of this value will cause an error
 }
 
 fn no_codegen<T>() {
-    if false {
-        let _ = PrintName::<T>::VOID; //~ERROR referenced constant has errors
+    if false { //~ERROR referenced constant has errors
+        let _ = PrintName::<T>::VOID;
     }
 }
 fn main() {