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

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

Index: pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
index 50b4b89d7944d212836c360f3309ab3136f35f49..e9e8865ed41026d46fe3c87b5c7505a5a4efe404 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
@@ -456,9 +456,9 @@ class SubexpressionVisitor extends ExpressionVisitor<String> {
   }
 
   String visitTypeOperator(TypeOperator node) {
-    String receiver = visitExpression(node.receiver);
+    String value = visitExpression(node.value);
     String type = "${node.type}";
-    return "TypeOperator $receiver ${node.operator} $type";
+    return "TypeOperator $value ${node.operator} $type";
   }
 
   String visitNot(Not node) {