raw_window_handle crashes on MacOS

[Goldenbough44]

The place error happens:

//raw_window_handle.rs
let ns_view = msg_send![ns_window as *mut NSObject, contentView];

Error messages:

invalid message send to -[SDL3Window contentView]: expected return to have type code '@', but found '^v'

This error didn't exist yesterday, I could run code without any problom. I think it is because of the version up of objc2 crate.

objc2 crate's latest docs(https://docs.rs/objc2/latest/objc2/macro.msg_send.html) says Type verification required for msg_send! macro, but 0.5.2 version(which is the minimal dependency version of sdl3 crate) docs(https://docs.rs/objc2/0.5.2/objc2/macro.msg_send.html) does not mentioned about it.

I think there are two options to handle this,

1. add dependency features for objc2 crate
   From the crate's docs: This behaviour can be tweaked with the "relax-void-encoding", "relax-sign-encoding" or "disable-encoding-assertions" Cargo feature flags if it is causing you trouble.

2. do type verification.

I think 2 would be good solution.

I didn't tested either solutions, but I think I can in some days. Can I make a branch for it and create PR?

[revmischa]

Please do!