Evaluate repeat expression lengths as late as possible

src/test/ui/consts/const-eval/const-eval-overflow-3.rs

@@ -19,6 +19,7 @@ const A_I8_I
     : [u32; (i8::MAX as usize) + 1]
     = [0; (i8::MAX + 1) as usize];
 //~^ ERROR evaluation of constant value failed
+//~| ERROR mismatched types
 
 fn main() {
     foo(&A_I8_I[..]);