Function make_zf_impl

fn make_zf_impl(
    sized_fields: &[FieldInfo<'_>],
    unsized_field_info: &UnsizedFields<'_>,
    fields: &Fields,
    name: &Ident,
    ule_name: &Ident,
    maybe_lt: Option<&Lifetime>,
    span: Span,
) -> TokenStream