cbindgen does not yield a valid header file

[shinaoka]

pub struct spir_kernel {
    pub(crate) inner: KernelType,
}

[shinaoka]

https://stackoverflow.com/questions/79253177/struct-foo-uint8-t-x0-versus-struct-foo-for-c-opaque-pointers-is-ther

[shinaoka]

https://crates.io/crates/ffi-opaque