Move the dart_precompiled function inside scoping function.

tests/language/deferred_shared_and_unshared_classes_test.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "package:expect/expect.dart";
+import "package:async_helper/async_helper.dart";
+import "deferred_shared_and_unshared_classes_lib1.dart" deferred as lib1;
+import "deferred_shared_and_unshared_classes_lib2.dart" deferred as lib2;
+import "dart:async";
+
+void main() {
+  asyncTest(() {
+    return Future.wait([
+      lib1.loadLibrary().then((_) {
+        lib1.foo();
+      }),
+      lib2.loadLibrary().then((_) {
+        lib2.foo();
+      })]);
+  });
+}