anchor.diff:    final Map<String, CompilationUnitElementImpl> resynthesizedUnits =
         <String, CompilationUnitElementImpl>{};
   
  -  /**
  -   * Types with implicit type arguments, which are the same as type parameter
  -   * bounds (in strong mode), or `dynamic` (in spec mode).
  -   */
  -  final Set<DartType> typesWithImplicitTypeArguments =
  -      new Set<DartType>.identity();
  -
     _LibraryResynthesizer(this.summaryResynthesizer, this.linkedLibrary,
         this.unlinkedUnits, this.librarySource) {
       libraryUri = librarySource.uri.toString();
  
positive.code: 
    @override
    bool doesTypeHaveImplicitArguments(ParameterizedType type) =>
        libraryResynthesizer.typesWithImplicitTypeArguments.contains(type);
  
    @override
    ConstructorElement getConstructorForInfo(
  
negative.code:       // Mark the type as having implicit type arguments, so that we don't
        // attempt to request them during constant expression resynthesizing.
        if (typeArguments == null) {
          _typesWithImplicitTypeArguments[type] = true;
        }
        // Done.
        return type;
  