Report const eval error inside the query

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

@@ -13,10 +13,9 @@
 const X: u32 = 5;
 const Y: u32 = 6;
 const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
-//~^ WARN this constant cannot be used
+//~^ WARN any use of this value will cause an error
 
 fn main() {
     println!("{}", FOO);
     //~^ ERROR
-    //~| ERROR
 }