Support `unsafe extern "C"` blocks

[Danvil]

Code generated by cc does not work with Rust Edition 2024 as extern "C" blocks now need to be unsafe.

Here is a related issue from the bindgen crate: rust-lang/rust-bindgen#3015

[NobodyXu]

Hmmm I didn't get it, which code generation are you referring to?

Is it the windows-sys bindings generated?