Run closed_world2_test using the normal compiler pipeline.

tests/compiler/dart2js/expect_annotations_test.dart

Index: tests/compiler/dart2js/expect_annotations_test.dart
diff --git a/tests/compiler/dart2js/expect_annotations_test.dart b/tests/compiler/dart2js/expect_annotations_test.dart
index 851dc65084de3950c6a90b881727a52b98c9113e..db049f8dea811ebe1920f26e831a555b83209b55 100644
--- a/tests/compiler/dart2js/expect_annotations_test.dart
+++ b/tests/compiler/dart2js/expect_annotations_test.dart
@@ -83,7 +83,8 @@ main() {
         TypeMask expectedParameterType: null,
         TypeMask expectedReturnType: null,
         bool expectAssumeDynamic: false}) {
-      Element method = compiler.mainApp.find(name);
+      LibraryElement mainApp = compiler.mainApp;
+      Element method = mainApp.find(name);
       Expect.isNotNull(method);
       Expect.equals(expectNoInline, backend.annotations.noInline(method),
           "Unexpected annotation of @NoInline on '$method'.");