[libcxx][modularisation] splits `<utility>` into self-contained headers
* moves `std::hash` and `std::unary_function` into `__functional`
* Everything else goes into `__utility/${NAME}.h`
Differential Revision: https://reviews.llvm.org/D104002
NOKEYCHECK=True
GitOrigin-RevId: 69d5a6662115499198ebfa07a081e98a6ce4b915
diff --git a/include/functional b/include/functional
index 249c0dc..2b2dcd2 100644
--- a/include/functional
+++ b/include/functional
@@ -490,7 +490,10 @@
#include <__config>
#include <__debug>
#include <__functional_base>
+#include <__functional/hash.h>
#include <__functional/search.h>
+#include <__functional/unary_function.h>
+#include <__functional/unwrap_ref.h>
#include <__utility/forward.h>
#include <concepts>
#include <exception>