{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"prev.build_mismatch_error(&hidden_ty,"}]}
                    prev.build_mismatch_error(&hidden_ty, self.tcx).map(|d| d.emit());
                let (Ok(guar) | Err(guar)) =
                prev.ty = Ty::new_error(self.tcx, guar);