Auto merge of rust-lang#117758 - Urgau:lint_pointer_trait_comparisons, r=davidtwco

Add lint against ambiguous wide pointer comparisons

This PR is the resolution of rust-lang#106447 decided in rust-lang#117717 by T-lang.

## `ambiguous_wide_pointer_comparisons`

*warn-by-default*

The `ambiguous_wide_pointer_comparisons` lint checks comparison of `*const/*mut ?Sized` as the operands.

### Example

```rust
let ab = (A, B);
let a = &ab.0 as *const dyn T;
let b = &ab.1 as *const dyn T;

let _ = a == b;
```

### Explanation

The comparison includes metadata which may not be expected.

-------

This PR also drops `clippy::vtable_address_comparisons` which is superseded by this one.

~~One thing: is the current naming right? `invalid` seems a bit too much.~~

Fixes rust-lang#117717

Author: bors

example/mini_core.rs

@@ -11,7 +11,7 @@
     thread_local
 )]
 #![no_core]
-#![allow(dead_code, internal_features)]
+#![allow(dead_code, internal_features, ambiguous_wide_pointer_comparisons)]
 
 #[lang = "sized"]
 pub trait Sized {}