Generate `nodiscard` for `#[must_use]` functions

[kpcyrd]

Hello!

Since C23 there's the nodiscard attribute, I was wondering if marking an exported Rust function with #[must_use] should also set this attribute in the generated header file.

Thanks!

[lu-zero]

that would be a great question for bindgen I guess.

[kpcyrd]

Good pointer, it seems there's rust-lang/rust-bindgen#2081 but only for types

[lu-zero]

I try to use the latest bindgen for the built-in support, in case another generator gets that first, you can still invoke it via build.rs and configure cargo-c to use the generated assets.