Fix "is Object" to always be true in Dart.

frog/type.dart

 // Copyright (c) 2011, 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.
 
 class Type implements Named, Hashable {
   final String name;
   bool isTested;
 
   /**
    * For core types (int, String, etc) this is the generated type assertion
@@ skipping 50 matching lines @@
   bool get isDouble() => false;
   bool get isVoid() => false;
 
   // True for all types in the Dart type system. We track non-nullabiltity
   // as an optimization for booleans to generate better code in checked mode.
   bool get isNullable() => true;
 
   // Strangely Dart treats calls on Function much like calls on var.
   bool get isVarOrFunction() => isVar || isFunction;
 
+  bool get isVarOrObject() => isVar || isObject;
+
   /** Gets the $call method for a function type. */
   MethodMember getCallMethod() => null;
 
   /** These types may not be implemented or extended by user code. */
   bool get isClosed() => isString || isBool || isNum || isFunction || isVar;
 
   bool get isUsed() => false;
 
   bool get isGeneric() => false;
   bool get isNativeType() => false;
@@ skipping 1172 matching lines @@
     var name = _getCallStubName('call', args);
     if (varStubs == null) varStubs = {};
     var stub = varStubs[name];
     if (stub == null) {
       stub = new VarFunctionStub(name, args);
       varStubs[name] = stub;
     }
     return stub;
   }
 }