anchor.diff:  
       result.fields.add(info);
       return info;
  +  }
  +
  +  bool _hasBeenResolved(MemberEntity entity) {
  +    return compiler.globalInference.typesInferrerInternal.inferrer.types
  +        .memberTypeInformations
  +        .containsKey(entity);
     }
   
     ClassInfo visitClass(ClassEntity clazz) {
  
positive.code:       compiler.globalInference.results.resultOfParameter(e);
  
    FieldInfo visitField(FieldEntity field) {
      if (!_hasBeenResolved(field)) return null;
      TypeMask inferredType = _resultOfMember(field).type;
      // If a field has an empty inferred type it is never used.
      if (inferredType == null || inferredType.isEmpty) return null;
  
negative.code:     return _infoFromOutputUnit(outputUnit);
    }
  
    bool _hasClassBeenResolved(ClassEntity cls) {
      return compiler.backend.mirrorsData.isClassResolved(cls);
    }
  