fix tests

Author: RalfJung

src/test/ui/consts/const-eval/ub-nonnull.rs

@@ -1,5 +1,5 @@
 #![feature(rustc_attrs, const_transmute)]
-#![allow(const_err)] // make sure we cannot allow away the errors tested here
+#![allow(const_err, invalid_value)] // make sure we cannot allow away the errors tested here
 
 use std::mem;
 use std::ptr::NonNull;

src/test/ui/consts/const-eval/ub-ref.rs

@@ -1,6 +1,6 @@
 // ignore-tidy-linelength
 #![feature(const_transmute)]
-#![allow(const_err)] // make sure we cannot allow away the errors tested here
+#![allow(const_err, invalid_value)] // make sure we cannot allow away the errors tested here
 
 use std::mem;
 

src/test/ui/consts/const-eval/ub-upvars.rs

@@ -1,5 +1,5 @@
 #![feature(const_transmute)]
-#![allow(const_err)] // make sure we cannot allow away the errors tested here
+#![allow(const_err, invalid_value)] // make sure we cannot allow away the errors tested here
 
 use std::mem;