Referring to erroneous constants in promoteds must abort the build

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

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-pass
 #![warn(const_err)]
 
 const X: u32 = 5;
@@ -20,4 +19,5 @@ const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
 fn main() {
     println!("{}", FOO);
     //~^ WARN this expression will panic at runtime
+    //~| ERROR erroneous constant used
 }