/// but you can only construct a `Interned` with `new_unchecked`, and not
/// directly.
#[derive(Debug)]
-#[cfg_attr(not(bootstrap), rustc_pass_by_value)]
+#[rustc_pass_by_value]
pub struct Interned<'a, T>(pub &'a T, pub private::PrivateZst);
impl<'a, T> Interned<'a, T> {