dart2js: fill in the basic functionality of the startup emitter.

pkg/compiler/lib/src/js_emitter/model.dart

Index: pkg/compiler/lib/src/js_emitter/model.dart
diff --git a/pkg/compiler/lib/src/js_emitter/model.dart b/pkg/compiler/lib/src/js_emitter/model.dart
index 46b43196178df534057d660a73edf5c6d01b0658..1c147e146bd548fa09d58105ac66e213c4864a5e 100644
--- a/pkg/compiler/lib/src/js_emitter/model.dart
+++ b/pkg/compiler/lib/src/js_emitter/model.dart
@@ -361,6 +361,12 @@ class Field {
 
   bool get needsInterceptedGetter => getterFlags > 1;
   bool get needsInterceptedSetter => setterFlags > 1;
+
+  bool get needsInterceptedGetterOnReceiver => getterFlags == 2;
+  bool get needsInterceptedSetterOnReceiver => setterFlags == 2;
+
+  bool get needsInterceptedGetterOnThis => getterFlags == 3;
+  bool get needsInterceptedSetterOnThis => setterFlags == 3;
 }
 
 abstract class Method {