{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
        let extern_abi = symbol_unescaped.as_str().parse().unwrap_or_else(|_| {
        let ast::StrLit { symbol_unescaped, span, .. } = abi_str;
            self.error_on_invalid_abi(abi_str);