20c833c632
The two altered expectation messages both seem like improvements: - `coerce-expect-unsized-ascribed.stderr` says you can go `Box<char> -> Box<dyn Debug>`, which you can. - `upcast_soundness_bug.stderr` used to say that you could go `Box<dyn Trait<u8, u8>> -> Box<dyn Trait>`, which you can't, because the type parameters are missing in the destination and the only ones that work aren't what's needed.