Correct stderr output for failing tests

Author: Mark-Simulacrum

src/test/ui/consts/const-eval/validate_uninhabited_zsts.rs

@@ -3,7 +3,7 @@
 
 const fn foo() -> ! {
     unsafe { std::mem::transmute(()) }
-    //~^ WARN any use of this value will cause an error [const_err]
+    //~^ ERROR evaluation of constant value failed
     //~| WARN the type `!` does not permit zero-initialization [invalid_value]
 }
 
@@ -12,7 +12,7 @@ enum Empty { }
 
 #[warn(const_err)]
 const FOO: [Empty; 3] = [foo(); 3];
-
+//~^ WARN any use of this value will cause an error
 #[warn(const_err)]
 const BAR: [Empty; 3] = [unsafe { std::mem::transmute(()) }; 3];
 //~^ ERROR it is undefined behavior to use this value

src/test/ui/consts/const-eval/validate_uninhabited_zsts.stderr

@@ -1,14 +1,16 @@
-warning: any use of this value will cause an error
+error[E0080]: evaluation of constant value failed
   --> $DIR/validate_uninhabited_zsts.rs:5:14
    |
 LL |     unsafe { std::mem::transmute(()) }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^
-   |              |
-   |              entering unreachable code
-   |              inside call to `foo` at $DIR/validate_uninhabited_zsts.rs:14:26
-...
+   |              ^^^^^^^^^^^^^^^^^^^^^^^ entering unreachable code
+
+warning: any use of this value will cause an error
+  --> $DIR/validate_uninhabited_zsts.rs:14:26
+   |
 LL | const FOO: [Empty; 3] = [foo(); 3];
-   | -----------------------------------
+   | -------------------------^^^^^-----
+   |                          |
+   |                          referenced constant has errors
    |
 note: lint level defined here
   --> $DIR/validate_uninhabited_zsts.rs:13:8
@@ -47,6 +49,6 @@ LL | const BAR: [Empty; 3] = [unsafe { std::mem::transmute(()) }; 3];
    |
    = note: 0-variant enums have no valid value
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.

src/test/ui/generator/async-generator-issue-67158.stderr

@@ -6,4 +6,3 @@ LL |     async { yield print!(":C") };
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0727`.