Object safety "method references the `Self` type" check does not normalize.

Example (using an associated type that matches a blanket `impl`):
```rust
trait Foo {
    type X;
}

impl<T: ?Sized> Foo for T {
    type X = ();
}

trait Bar {
    // Note how this is allowed without a bound.
    fn foo(&self) -> <Self as Foo>::X;
}

// error: the trait `Bar` cannot be made into an object
fn foo(_: Box<dyn Bar>) {}

fn main() {}
```