Support runtime check of function types.

sdk/lib/_internal/compiler/implementation/compiler.dart

Index: sdk/lib/_internal/compiler/implementation/compiler.dart
diff --git a/sdk/lib/_internal/compiler/implementation/compiler.dart b/sdk/lib/_internal/compiler/implementation/compiler.dart
index b51e9f5923e46a809e3716a7e9d61ed9dae3dcc0..807f8b5d41792faee9dbda76c8845810336bd874 100644
--- a/sdk/lib/_internal/compiler/implementation/compiler.dart
+++ b/sdk/lib/_internal/compiler/implementation/compiler.dart
@@ -127,6 +127,7 @@ abstract class Backend {
   }
 
   bool needsRti(ClassElement cls);
+  bool methodNeedsRti(Element cls);
 
   // The following methods are hooks for the backend to register its
   // helper methods.
@@ -152,7 +153,22 @@ abstract class Backend {
   void registerFallThroughError(TreeElements elements) {}
   void registerSuperNoSuchMethod(TreeElements elements) {}
   void registerConstantMap(TreeElements elements) {}
-  void registerRuntimeType(TreeElements elements) {}
+  /**
+   * Call this to register that an instantiated generic class has a call
+   * method.
+   */
+  void registerGenericCallMethod(Element callMethod,
+                                 Enqueuer enqueuer, TreeElements elements) {}
+  /**
+   * Call this to register that a getter exists for a function on an
+   * instantiated generic class.
+   */
+  void registerGenericClosure(Element closure,
+                              Enqueuer enqueuer, TreeElements elements) {}
+  /**
+   * Call this to register that the [:runtimeType:] property has been accessed.
+   */
+  void registerRuntimeType(Enqueuer enqueuer, TreeElements elements) {}
 
   void registerRequiredType(DartType type, Element enclosingElement) {}
   void registerClassUsingVariableExpression(ClassElement cls) {}