Function compute_c_abi_info

pub(crate) fn compute_c_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
where
    Ty: TyAbiInterface<'a, C> + Copy,
    C: HasDataLayout,

The purpose of this ABI is to match the C ABI (aka clang) exactly.