{"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"///"}]}
    /// false but technically valid for typeck.
    /// sure we consider `dyn Trait: Sized` where clauses, which are trivially
    fn is_return_ty_definitely_unsized(&self, fcx: &FnCtxt<'_, 'tcx>) -> bool {