Put ice test auxiliary fix in right place

tests/ui/crashes/auxiliary/ice-4727-aux.rs

@@ -1,7 +1,3 @@
-//ignore-test
-
-// This file is used by the ice-4727 test but isn't itself a test.
-//
 pub trait Trait {
     fn fun(par: &str) -> &str;
 }

tests/ui/crashes/ice-4727.rs

@@ -2,7 +2,7 @@
 
 #![warn(clippy::use_self)]
 
-#[path = "ice-4727-aux.rs"]
+#[path = "auxiliary/ice-4727-aux.rs"]
 mod aux;
 
 fn main() {}