improve xcode_emulation.py

test/mac/clang-cxx-language-standard/c++98.cc

Index: test/mac/clang-cxx-language-standard/c++98.cc
diff --git a/test/mac/clang-cxx-language-standard/c++98.cc b/test/mac/clang-cxx-language-standard/c++98.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a6a00c70f497f37bf5e8bafc3d9af48f8ea7030f
--- /dev/null
+++ b/test/mac/clang-cxx-language-standard/c++98.cc
@@ -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.
+
+#if __cplusplus != 199711L
+#error wrong c++ standard version
+#endif
+
+enum cxx11_keywords {
+  alignas,
+  alignof,
+  char16_t,
+  char32_t,
+  constexpr,
+  decltype,
+  noexcept,
+  nullptr,
+  override,
+  static_assert,
+  thread_local,
+};
+
+int main() { return 0; }
+