anchor.diff:  /// Special case of [_PropertyAccessor] to avoid creating an indirect access to
   /// 'this'.
   class ThisPropertyAccessGenerator<Arguments> extends Generator<Arguments> {
  -  Name name;
  -
  -  Member getter;
  -
  -  Member setter;
  +  final Name name;
  +
  +  final Member getter;
  +
  +  final Member setter;
   
     ThisPropertyAccessGenerator(BuilderHelper<dynamic, dynamic, Arguments> helper,
         Token token, this.name, this.getter, this.setter)
  
positive.code:     with FastaAccessor<Arguments>;
  
  class VariableUseGenerator<Arguments> extends Generator<Arguments> {
    VariableDeclaration variable;
    DartType promotedType;
  
    VariableUseGenerator(BuilderHelper<dynamic, dynamic, Arguments> helper,
        Token token, this.variable,
  
negative.code: 
  class PropertyAccessGenerator<Arguments> extends Generator<Arguments> {
    VariableDeclaration _receiverVariable;
  
    final kernel.Expression receiver;
  
    final Name name;
  
    final Member getter;
  
    final Member setter;
  
    PropertyAccessGenerator.internal(
        BuilderHelper<dynamic, dynamic, Arguments> helper,
  