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

pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart

Index: pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
index c2e67b79e046a8c5be4abdd3ad8bf05495631959..aebbd23edc312f698cbafebff943e21718015272 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
@@ -332,11 +332,13 @@ class LiteralMap extends Expression {
 
 /// Given the interceptor for a value, test the value against a type.
 class TypeOperator extends Expression {
-  Expression receiver;
+  Expression value;
   final DartType type;
+  final List<Expression> typeArguments;
   final bool isTypeTest;
 
-  TypeOperator(this.receiver, this.type, {bool this.isTypeTest});
+  TypeOperator(this.value, this.type, this.typeArguments,
+               {bool this.isTypeTest});
 
   accept(ExpressionVisitor visitor) => visitor.visitTypeOperator(this);
   accept1(ExpressionVisitor1 visitor, arg) {
@@ -1157,7 +1159,8 @@ abstract class RecursiveVisitor implements StatementVisitor, ExpressionVisitor {
   }
 
   visitTypeOperator(TypeOperator node) {
-    visitExpression(node.receiver);
+    visitExpression(node.value);
+    node.typeArguments.forEach(visitExpression);
   }
 
   visitFunctionExpression(FunctionExpression node) {
@@ -1349,7 +1352,8 @@ class RecursiveTransformer extends Transformer {
   }
 
   visitTypeOperator(TypeOperator node) {
-    node.receiver = visitExpression(node.receiver);
+    node.value = visitExpression(node.value);
+    _replaceExpressions(node.typeArguments);
     return node;
   }