{"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"//"}]}
                // type applicable to `op`.
                // point. Passing `lhs_ty` as both operands just to check if `lhs_ty` is a builtin
                let ret_ty = if self.is_builtin_binop(&lhs_ty, &lhs_ty, op) {