Add a type kind to TypedSelector. A typed selector can either be

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

Index: sdk/lib/_internal/compiler/implementation/enqueue.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/enqueue.dart	(revision 18249)
+++ sdk/lib/_internal/compiler/implementation/enqueue.dart	(working copy)
@@ -354,9 +354,10 @@
                            DartType type) {
     task.measure(() {
       Selector getter = new Selector.getter(getterName, library);
-      registerNewSelector(getterName,
-                          new TypedSelector(type, getter),
-                          universe.fieldGetters);
+      registerNewSelector(
+          getterName,
+          new TypedSelector(type, TypedSelectorKind.SUBCLASS, getter),
+          universe.fieldGetters);
     });
   }
 
@@ -365,9 +366,10 @@
                            DartType type) {
     task.measure(() {
       Selector setter = new Selector.setter(setterName, library);
-      registerNewSelector(setterName,
-                          new TypedSelector(type, setter),
-                          universe.fieldSetters);
+      registerNewSelector(
+          setterName,
+          new TypedSelector(type, TypedSelectorKind.SUBCLASS, setter),
+          universe.fieldSetters);
     });
   }