Adjust tests for newly added ambiguous_wide_pointer_comparisons lint

Author: Urgau

alloc/tests/vec.rs

@@ -1974,7 +1974,7 @@ fn vec_macro_repeating_null_raw_fat_pointer() {
 
     let vec = vec![null_raw_dyn; 1];
     dbg!(ptr_metadata(vec[0]));
-    assert!(vec[0] == null_raw_dyn);
+    assert!(std::ptr::eq(vec[0], null_raw_dyn));
 
     // Polyfill for https://github.com/rust-lang/rfcs/pull/2580