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

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

NOKEYCHECK=True
GitOrigin-RevId: 050b064f15ee56ee0b42c9b957a3dd0f32532394
diff --git a/include/memory b/include/memory
index 62dd992..4f73a81 100644
--- a/include/memory
+++ b/include/memory
@@ -672,6 +672,7 @@
 #include <__memory/addressof.h>
 #include <__memory/allocation_guard.h>
 #include <__memory/allocator.h>
+#include <__memory/allocator_arg_t.h>
 #include <__memory/allocator_traits.h>
 #include <__memory/compressed_pair.h>
 #include <__memory/construct_at.h>
@@ -682,6 +683,7 @@
 #include <__memory/temporary_buffer.h>
 #include <__memory/uninitialized_algorithms.h>
 #include <__memory/unique_ptr.h>
+#include <__memory/uses_allocator.h>
 #include <compare>
 #include <cstddef>
 #include <cstdint>