Tests that the object-safety assertion via `impl dyn` is working:

```rust compile_fail
trait ObjectUnsafe: Sized {}

#[dynamize::dynamize]
trait Trait: ObjectUnsafe {}
```

```rust compile_fail
trait ObjectUnsafe: Sized {}

#[dynamize::dynamize]
trait Trait {
    type A: ObjectUnsafe;

    fn f(&self) -> Self::A;
}
```