Handle platform access through prefix in dart2dart

tests/language/regress_21998_lib1.dart

Index: tests/language/regress_21998_lib1.dart
diff --git a/pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart b/tests/language/regress_21998_lib1.dart
similarity index 51%
copy from pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
copy to tests/language/regress_21998_lib1.dart
index 1a07d2bfcbec000ca259946fd3598f181039ec0b..ef3d8690d7c4285504aa0cf5ed5f6c72a8918cea 100644
--- a/pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
+++ b/tests/language/regress_21998_lib1.dart
@@ -1,9 +1,7 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
-library test_lib2_bar;
+library regress_21998_lib1;
 
-class Bar {
-
-}
+String max(String a, String b, String c) => '$a$b$c';