Mark is_final as a C++14 feature.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@202991 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/type_traits b/include/type_traits
index 63ab138..660ed86 100644
--- a/include/type_traits
+++ b/include/type_traits
@@ -762,7 +762,7 @@
 
 // is_final
 
-#if __has_feature(is_final)
+#if _LIBCPP_STD_VER > 11 && __has_feature(is_final)
 template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY 
 is_final : public integral_constant<bool, __is_final(_Tp)> {};
 #endif
diff --git a/test/utilities/meta/meta.unary/meta.unary.prop/is_final.pass.cpp b/test/utilities/meta/meta.unary/meta.unary.prop/is_final.pass.cpp
index 2f69c74..cf32196 100644
--- a/test/utilities/meta/meta.unary/meta.unary.prop/is_final.pass.cpp
+++ b/test/utilities/meta/meta.unary/meta.unary.prop/is_final.pass.cpp
@@ -13,7 +13,7 @@
 
 #include <type_traits>
 
-#if __cplusplus >= 201103L
+#if _LIBCPP_STD_VER > 11
 
 struct P final { };
 union U1 { };