dart2js cps_ir: Use interceptors for is-checks (version 2)

pkg/compiler/lib/src/js_backend/codegen/unsugar.dart

 library dart2js.unsugar_cps;
 
 import '../../cps_ir/cps_ir_nodes.dart';
 
 import '../../cps_ir/optimizers.dart' show ParentVisitor, Pass;
 import '../../constants/values.dart';
 import '../../elements/elements.dart';
 import '../../io/source_information.dart';
 import '../../js_backend/codegen/glue.dart';
 import '../../universe/selector.dart' show Selector;
@@ skipping 211 matching lines @@
     // Rethrow can only appear in a catch block.  It throws that block's
     // (wrapped) caught exception.
     Throw replacement = new Throw(_exceptionParameter);
     InteriorNode parent = node.parent;
     parent.body = replacement;
     replacement.parent = parent;
     // The original rethrow does not have any references that we need to
     // worry about unlinking.
   }
 
+  // TODO(24523): Insert interceptor on demand when we discover we want to use
+  // one rather than on every check.
+  processTypeTest(TypeTest node) {
+    assert(node.interceptor == null);
+    Primitive receiver = node.value.definition;
+    Primitive interceptor = new Interceptor(receiver, node.sourceInformation)
+        ..interceptedClasses.addAll(_glue.interceptedClasses);
+    insertLetPrim(interceptor, node.parent);
+    node.interceptor = new Reference<Primitive>(interceptor);
+    node.interceptor.parent = node;
+  }
+
   processInvokeMethod(InvokeMethod node) {
     Selector selector = node.selector;
     if (!_glue.isInterceptedSelector(selector)) return;
 
     Primitive receiver = node.receiver.definition;
     Primitive newReceiver;
 
     if (receiver == explicitReceiverParameter) {
       // If the receiver is the explicit receiver, we are calling a method in
       // the same interceptor:
@@ skipping 35 matching lines @@
       insertLetPrim(newReceiver, contBinding);
     }
     node.arguments.insert(0, node.receiver);
     node.receiver = new Reference<Primitive>(newReceiver);
   }
 
   processInterceptor(Interceptor node) {
     _glue.registerSpecializedGetInterceptor(node.interceptedClasses);
   }
 }