Move <optional> into include/experimental, and into the std::experimental namespace, since it's not part of C++14, but of an upcoming TS

llvm-svn: 194867

libcxx/test/utilities/optional/optional.object/optional_not_destructible.fail.cpp

@@ -11,10 +11,12 @@
 
 // T shall be an object type and shall satisfy the requirements of Destructible
 
-#include <optional>
+#include <experimental/optional>
 
 #if _LIBCPP_STD_VER > 11
 
+using std::experimental::optional;
+
 struct X
 {
 private:
@@ -26,7 +28,7 @@ private:
 int main()
 {
 #if _LIBCPP_STD_VER > 11
-    std::optional<X> opt;
+    optional<X> opt;
 #else
 #error
 #endif  // _LIBCPP_STD_VER > 11