dart2js cps: 'is' checks on types with type arguments.

pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.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.
 
 part of tree_ir.optimization;
 
 /**
  * Performs the following transformations on the tree:
  * - Assignment inlining
  * - Assignment expression propagation
@@ skipping 554 matching lines @@
   Expression visitLiteralMap(LiteralMap node) {
     // Process arguments right-to-left, the opposite of evaluation order.
     for (LiteralMapEntry entry in node.entries.reversed) {
       entry.value = visitExpression(entry.value);
       entry.key = visitExpression(entry.key);
     }
     return node;
   }
 
   Expression visitTypeOperator(TypeOperator node) {
-    node.receiver = visitExpression(node.receiver);
+    _rewriteList(node.typeArguments);
+    node.value = visitExpression(node.value);
     return node;
   }
 
   Expression visitSetField(SetField node) {
     node.value = visitExpression(node.value);
     node.object = visitExpression(node.object);
     return node;
   }
 
   Expression visitGetField(GetField node) {
@@ skipping 336 matching lines @@
 }
 
 /// Result of combining two expressions that do not affect reference counting.
 class GenericCombinedExpressions implements CombinedExpressions {
   Expression combined;
 
   GenericCombinedExpressions(this.combined);
 
   void uncombine() {}
 }