[feature] Error message for non-wasm32-unknown-unknown compatible crates

[bicarlsen]

Currently if a crate is not wasm32-unknown-unknown compatible, strange errors can be seen (See this issue on Tauri).

Would it be possible to check if a crate or any of its dependencies are not compatible with the wasm32-unknown-unknown target and return an error message indicating as such?

[ctron]

Hm, I am wondering how we could actually detect this. You can just compile any crate to any target, unless it then fails due to some build errors.