Add a #library in new tests with an #import, as required by Chromium.

tests/language/src/Library5Test.dart

 // Copyright (c) 2011, 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.
 //
 
+#library("Library5Test.dart");
 #import("Library5a.dart", prefix : "lib5a");
 #import("Library5b.dart", prefix : "lib5b");
 
 int foo(lib5a.Fun f) {
   return f();
 }
 
 int bar(lib5b.Fun f) {
   return f(42);
 }
 
 main() {
   Expect.equals(41, foo(() => 41));
   Expect.equals(42, bar((x) => x));
 }