dart2js cps_ir: Use interceptors for is-checks.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
index 19b0543c179877ab2a4d7ba2c7061d8822b6f116..13b28215270d72dd834259a9c3d8c9a0776af93c 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
@@ -587,6 +587,7 @@ class Refinement extends Primitive {
 /// to simplify code generation for type tests.
 class TypeTest extends Primitive {
   Reference<Primitive> value;
+
   final DartType dartType;
 
   /// If [type] is an [InterfaceType], this holds the internal representation of
@@ -605,8 +606,8 @@ class TypeTest extends Primitive {
   TypeTest(Primitive value,
            this.dartType,
            List<Primitive> typeArguments)
-  : this.value = new Reference<Primitive>(value),
-    this.typeArguments = _referenceList(typeArguments);
+      : this.value = new Reference<Primitive>(value),
+        this.typeArguments = _referenceList(typeArguments);
 
   accept(Visitor visitor) => visitor.visitTypeTest(this);
 
@@ -614,6 +615,35 @@ class TypeTest extends Primitive {
   bool get isSafeForReordering => true;
 }
 
+/// An "is" type test for a raw type.
+///
+/// Returns `true` if [value] is an instance of [type].
+///
+/// [type] must not be the [Object], `dynamic` or [Null] types (though it might
+/// be a type variable containing one of these types). This design is chosen
+/// to simplify code generation for type tests.
+class TypeTestRaw extends Primitive {
+  //
+  Reference<Primitive> value;
+
+  // Some tests can be performed on the interceptor by testing a property.  May
+  // be null for other tests.  The interceptor may have been optimized via the
+  // self-interceptor rule to [value].
+  Reference<Primitive> interceptor;
+
+  final DartType dartType;
+
+  bool usePropertyTest = false;
+
+  TypeTestRaw(Primitive value, this.dartType)
+      : this.value = new Reference<Primitive>(value);
+
+  accept(Visitor visitor) => visitor.visitTypeTestRaw(this);
+
+  bool get isSafeForElimination => true;
+  bool get isSafeForReordering => true;
+}
+
 /// An "as" type cast.
 ///
 /// If [value] is `null` or is an instance of [type], [continuation] is invoked
@@ -1371,6 +1401,7 @@ abstract class Visitor<T> {
   T visitTypeExpression(TypeExpression node);
   T visitCreateInvocationMirror(CreateInvocationMirror node);
   T visitTypeTest(TypeTest node);
+  T visitTypeTestRaw(TypeTestRaw node);
   T visitApplyBuiltinOperator(ApplyBuiltinOperator node);
   T visitApplyBuiltinMethod(ApplyBuiltinMethod node);
   T visitGetLength(GetLength node);
@@ -1499,6 +1530,13 @@ class LeafVisitor implements Visitor {
     node.typeArguments.forEach(processReference);
   }
 
+  processTypeTestRaw(TypeTestRaw node) {}
+  visitTypeTestRaw(TypeTestRaw node) {
+    processTypeTestRaw(node);
+    processReference(node.value);
+    if (node.interceptor != null) processReference(node.interceptor);
+  }
+
   processSetMutable(SetMutable node) {}
   visitSetMutable(SetMutable node) {
     processSetMutable(node);