Configure to get along with 2.9 clang

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@136526 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index 0c46f76..ced9a95 100644
--- a/include/__config
+++ b/include/__config
@@ -146,6 +146,9 @@
 
 #if !(__has_feature(cxx_auto_type))
 #define _LIBCPP_HAS_NO_AUTO_TYPE
+#endif
+
+#if __clang_major__ < 3
 #define _LIBCPP_HAS_NO_ADVANCED_SFINAE
 #endif