{"ast_node_type":"other","tokens":[{"end":18,"kind":"keyword","start":0,"text":"_"}]}
            _ => {
                .inline_attr_str_error_with_macro_def(hir_id, attr_span, "allow_internal_unstable"),
                self.tcx.dcx().emit_err(errors::RustcAllowConstFnUnstable { attr_span, span });