{"ast_node_type":"variable","tokens":[{"end":57,"kind":"keyword","start":0,"text":"let"}]}
            let va_list_arg_idx = self.fn_abi.args.len();
            // The `VaList` "spoofed" argument is just after all the real arguments.
            match self.locals[mir::Local::from_usize(1 + va_list_arg_idx)] {