anchor.diff:        compiler.globalInference.results.resultOfParameter(e);
   
     FieldInfo visitField(FieldEntity field) {
  -    if (!_hasBeenResolved(field)) return null;
  +    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;
  
positive.code: 
      result.fields.add(info);
      return info;
    }
  
    ClassInfo visitClass(ClassEntity clazz) {
  
negative.code:     return _infoFromOutputUnit(outputUnit);
    }
  
    bool _hasClassBeenResolved(ClassEntity cls) {
      return compiler.backend.mirrorsData.isClassResolved(cls);
    }
  