anchor.diff:    }
   
     @override
  -  visitSetLiteral(SetLiteral node) {
  +  JS.Expression visitSetLiteral(SetLiteral node) {
       // TODO(markzipan): remove const check when we use front-end const eval
       if (!node.isConst) {
         var setType = visitInterfaceType(
  
positive.code:   }
  
    @override
    visitLoadLibrary(LoadLibrary node) => runtimeCall('loadLibrary()');
  
    // TODO(jmesserly): DDC loads all libraries eagerly.
    // See
    // https://github.com/dart-lang/sdk/issues/27776
    // https://github.com/dart-lang/sdk/issues/27777
    @override
    visitCheckLibraryIsLoaded(CheckLibraryIsLoaded node) => js.boolean(true);
  
    bool _reifyFunctionType(FunctionNode f) {
      if (_currentLibrary.importUri.scheme != 'dart') return true;
  
negative.code:   }
  
    @override
    JS.Expression visitSymbolLiteral(SymbolLiteral node) =>
        emitDartSymbol(node.value);
  
    @override
    JS.Expression visitTypeLiteral(TypeLiteral node) =>
        _emitTypeLiteral(node.type);
  
    JS.Expression _emitTypeLiteral(DartType type) {
      var typeRep = _emitType(type);
  