Function const_of_item_or_delayed_bug 

pub fn const_of_item_or_delayed_bug<'tcx>(
    tcx: TyCtxt<'tcx>,
    def_id: DefId,
) -> EarlyBinder<'tcx, Const<'tcx>>

The old solver does not support references to non-type-consts. Emit a delayed bug if there is a type system reference to a non type const, as this should have already errored elsewhere.