Dummy receiver optimization

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

Index: sdk/lib/_internal/compiler/implementation/js_backend/constant_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/constant_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_backend/constant_emitter.dart
index c6ee2e53fac5049cff9b4bc3d69092659f26a327..c436744568879d38f091b46fdfefd3bcd1cc82cb 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/constant_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/constant_emitter.dart
@@ -144,6 +144,10 @@ class ConstantReferenceEmitter implements ConstantVisitor<jsAst.Expression> {
   jsAst.Expression visitInterceptor(InterceptorConstant constant) {
     return emitCanonicalVersion(constant);
   }
+
+  jsAst.Expression visitDummyReceiver(DummyReceiverConstant constant) {
+    return new jsAst.LiteralNumber('0');
+  }
 }
 
 /**
@@ -313,6 +317,10 @@ class ConstantInitializerEmitter implements ConstantVisitor<jsAst.Expression> {
         'prototype');
   }
 
+  jsAst.Expression visitDummyReceiver(DummyReceiverConstant constant) {
+    return _reference(constant);
+  }
+
   jsAst.Expression visitConstructed(ConstructedConstant constant) {
     Element element = constant.type.element;
     if (element.isForeign(compiler)