Fix invalid cast

pkg/analyzer/lib/src/dart/constant/value.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * The implementation of the class [DartObject].
  */
 library analyzer.src.dart.constant.value;
 
 import 'dart:collection';
@@ skipping 126 matching lines @@
 
 /**
  * A representation of an instance of a Dart class.
  */
 class DartObjectImpl implements DartObject {
   /**
    * An empty list of objects.
    */
   static const List<DartObjectImpl> EMPTY_LIST = const <DartObjectImpl>[];
 
-  /**
-   * The run-time type of this object.
-   */
   @override
   final ParameterizedType type;
 
   /**
    * The state of the object.
    */
   final InstanceState _state;
 
   /**
    * Initialize a newly created object to have the given [type] and [_state].
    */
   DartObjectImpl(this.type, this._state);
 
   /**
    * Create an object to represent an unknown value.
    */
-  factory DartObjectImpl.validWithUnknownValue(InterfaceType type) {
+  factory DartObjectImpl.validWithUnknownValue(ParameterizedType type) {
     if (type.element.library.isDartCore) {
       String typeName = type.name;
       if (typeName == "bool") {
         return new DartObjectImpl(type, BoolState.UNKNOWN_VALUE);
       } else if (typeName == "double") {
         return new DartObjectImpl(type, DoubleState.UNKNOWN_VALUE);
       } else if (typeName == "int") {
         return new DartObjectImpl(type, IntState.UNKNOWN_VALUE);
       } else if (typeName == "String") {
         return new DartObjectImpl(type, StringState.UNKNOWN_VALUE);
@@ skipping 2634 matching lines @@
       return BoolState.from(_type == rightType);
     } else if (rightOperand is DynamicState) {
       return BoolState.UNKNOWN_VALUE;
     }
     return BoolState.FALSE_STATE;
   }
 
   @override
   String toString() => _type?.toString() ?? "-unknown-";
 }