/** Creates an operator symbol. */
 private Symbol makeOperator(
     Name name, List<OperatorType> formals, OperatorType res, int... opcodes) {
   MethodType opType =
       new MethodType(
           formals.stream().map(o -> o.asType(syms)).collect(List.collector()),
           res.asType(syms),
           List.nil(),
           syms.methodClass);
   return new OperatorSymbol(name, opType, mergeOpcodes(opcodes), syms.noSymbol);
 }