Bless compile-fail

Author: ecstatic-morse

src/test/compile-fail/consts/const-fn-error.rs

@@ -5,9 +5,7 @@ const X : usize = 2;
 const fn f(x: usize) -> usize {
     let mut sum = 0;
     for i in 0..x {
-        //~^ ERROR E0015
-        //~| ERROR E0015
-        //~| ERROR E0658
+        //~^ ERROR mutable references
         //~| ERROR E0080
         //~| ERROR E0744
         sum += i;