1e3d632f8f
Check that a box expression's type is Sized This resolves [issue 87935](https://github.com/rust-lang/rust/issues/87935). This makes E0161 (move from an unsized rvalue) much less common. I've replaced the test to use [this case](https://github.com/rust-lang/rust/blob/master/src/test/ui/object-safety/object-safety-by-value-self-use.rs), when a boxed `dyn` trait is passed by value, but that isn't an error when `unsized_locals` is enabled. I think it may be possible to get rid of E0161 entirely by checking that case earlier, but I'm not sure if that's desirable?