code: private OperatorSymbol reportErrorIfNeeded(DiagnosticPosition pos, Tag tag, Type... args) {
          if (Stream.of(args).noneMatch(Type::isErroneous)) {
              Name opName = operatorName(tag);
              JCDiagnostic.Error opError = (args.length) == 1 ?
                      Errors.OperatorCantBeApplied(opName, args[0]) :
                      Errors.OperatorCantBeApplied1(opName, args[0], args[1]);
              log.error(pos, opError);
          }
          return noOpSymbol;
      }
docs: Report an operator lookup error.