[libcxx][functional][modular] splices <functional> into modular headers

Differential Revision: https://reviews.llvm.org/D104942

NOKEYCHECK=True
GitOrigin-RevId: 050b064f15ee56ee0b42c9b957a3dd0f32532394
diff --git a/include/queue b/include/queue
index 3c7bbf2..42470e3 100644
--- a/include/queue
+++ b/include/queue
@@ -179,6 +179,7 @@
 */
 
 #include <__config>
+#include <__memory/uses_allocator.h>
 #include <__utility/forward.h>
 #include <algorithm>
 #include <compare>