Enable moving monostate from C++17

Author: AmrDeveloper

libcxx/include/utility

@@ -267,6 +267,7 @@ template <class T>
 #  if _LIBCPP_STD_VER >= 17
 #    include <__utility/as_const.h>
 #    include <__utility/in_place.h>
+#    include <__variant/monostate.h>
 #  endif
 
 #  if _LIBCPP_STD_VER >= 20
@@ -279,10 +280,6 @@ template <class T>
 #    include <__utility/unreachable.h>
 #  endif
 
-#  if _LIBCPP_STD_VER >= 26
-#    include <__variant/monostate.h>
-#  endif
-
 #  include <version>
 
 // standard-mandated includes

libcxx/test/libcxx/transitive_includes/cxx17.csv

@@ -640,6 +640,7 @@ experimental/utility compare
 experimental/utility cstddef
 experimental/utility cstdint
 experimental/utility cstdlib
+experimental/utility cstring
 experimental/utility initializer_list
 experimental/utility iosfwd
 experimental/utility limits
@@ -2501,6 +2502,7 @@ utility compare
 utility cstddef
 utility cstdint
 utility cstdlib
+utility cstring
 utility initializer_list
 utility iosfwd
 utility limits

libcxx/test/libcxx/transitive_includes/cxx20.csv

@@ -636,6 +636,7 @@ experimental/utility compare
 experimental/utility cstddef
 experimental/utility cstdint
 experimental/utility cstdlib
+experimental/utility cstring
 experimental/utility initializer_list
 experimental/utility iosfwd
 experimental/utility limits
@@ -2529,6 +2530,7 @@ utility compare
 utility cstddef
 utility cstdint
 utility cstdlib
+utility cstring
 utility initializer_list
 utility iosfwd
 utility limits

libcxx/test/libcxx/transitive_includes/cxx23.csv

@@ -301,6 +301,7 @@ experimental/type_traits type_traits
 experimental/type_traits version
 experimental/utility compare
 experimental/utility cstdint
+experimental/utility cstring
 experimental/utility initializer_list
 experimental/utility limits
 experimental/utility utility
@@ -1116,6 +1117,7 @@ unordered_set tuple
 unordered_set version
 utility compare
 utility cstdint
+utility cstring
 utility initializer_list
 utility limits
 utility version

libcxx/test/std/utilities/utility/utility.monostate.relpos/relops.pass.cpp

@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23
+// REQUIRES: std-at-least-c++17
 
 // <utility>
 

libcxx/test/std/utilities/utility/utility.monostate/monostate.pass.cpp

@@ -7,7 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23
+// REQUIRES: std-at-least-c++17
 
 // <utility>