pub trait ArgAbiBuilderMethods<'tcx>: BackendTypes {
    // Required methods
    fn store_fn_arg(
        &mut self,
        arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
        idx: &mut usize,
        dst: PlaceRef<'tcx, Self::Value>,
    );
    fn store_arg(
        &mut self,
        arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
        val: Self::Value,
        dst: PlaceRef<'tcx, Self::Value>,
    );
}