Add a comment documenting the hacky test of `()` from ToRustTy
Add a comment documenting the hacky test of `()` from ToRustTy

emilio/rust-bindgen,emilio/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,rust-lang/rust-bindgen