[NFC][libc++] Moves transitive includes location.

As discussed in D132284 they will be moved to the end.

Reviewed By: #libc, Mordante

Differential Revision: https://reviews.llvm.org/D133212

NOKEYCHECK=True
GitOrigin-RevId: e31c2a1b1a643861f25ba0145cb4701c999fc6c2
diff --git a/include/stack b/include/stack
index a4a76e5..8f0a997 100644
--- a/include/stack
+++ b/include/stack
@@ -107,10 +107,6 @@
 #include <type_traits>
 #include <version>
 
-#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
-#  include <functional>
-#endif
-
 // standard-mandated includes
 #include <compare>
 #include <initializer_list>
@@ -363,4 +359,8 @@
 
 _LIBCPP_END_NAMESPACE_STD
 
+#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
+#  include <functional>
+#endif
+
 #endif // _LIBCPP_STACK