Change how _LIBCPP_HAS_NO_ADVANCED_SFINAE gets set.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@136596 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index ced9a95..2f75ed8 100644
--- a/include/__config
+++ b/include/__config
@@ -148,7 +148,7 @@
 #define _LIBCPP_HAS_NO_AUTO_TYPE
 #endif
 
-#if __clang_major__ < 3
+#if !(__has_feature(cxx_access_control_sfinae)) || !__has_feature(cxx_trailing_return)
 #define _LIBCPP_HAS_NO_ADVANCED_SFINAE
 #endif