anchor.diff:   * Element representing a constructor resynthesized from a summary
    * during linking.
    */
  -class ConstructorElementForLink extends ExecutableElementForLink
  +class ConstructorElementForLink extends ExecutableElementForLink_NonLocal
       with ReferenceableElementForLink
       implements ConstructorElementImpl {
     /**
  
positive.code:     }
      return _displayName;
    }
  
    @override
    Element get enclosingElement => enclosingClass ?? compilationUnit;
  
    @override
    TypeParameterizedElementForLink get enclosingTypeParameterContext =>
        enclosingClass;
  
    @override
    bool get hasImplicitReturnType => _unlinkedExecutable.returnType == null;
  
negative.code:  * Specialization of [PropertyAccessorElementForLink] for non-synthetic
   * accessors explicitly declared in the source code.
   */
  class PropertyAccessorElementForLink_Executable
      extends ExecutableElementForLink_NonLocal
      with ReferenceableElementForLink
      implements PropertyAccessorElementForLink {
    @override
  