improve xcode_emulation.py

test/mac/clang-cxx-library/clang-cxx-library.gyp

Index: test/mac/clang-cxx-library/clang-cxx-library.gyp
diff --git a/test/mac/clang-cxx-library/clang-cxx-library.gyp b/test/mac/clang-cxx-library/clang-cxx-library.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..6a901b128a8d0b5541ec1310474c9e57c572e507
--- /dev/null
+++ b/test/mac/clang-cxx-library/clang-cxx-library.gyp
@@ -0,0 +1,24 @@
+# Copyright (c) 2013 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+{
+  'targets': [
+    {
+      'target_name': 'libc++',
+      'type': 'executable',
+      'sources': [ 'libc++.cc', ],
+      'xcode_settings': {
+        'CLANG_CXX_LIBRARY': 'libc++',
+      },
+    },
+    {
+      'target_name': 'libstdc++',
+      'type': 'executable',
+      'sources': [ 'libstdc++.cc', ],
+      'xcode_settings': {
+        'CLANG_CXX_LIBRARY': 'libstdc++',
+      },
+    },
+  ],
+}
+