[libc++] Fix stray usage of _LIBCPP_HAS_NO_WIDE_CHARACTERS on Windows

Author: ldionne

libcxx/include/__locale_dir/support/windows.h

@@ -215,7 +215,7 @@ inline _LIBCPP_HIDE_FROM_ABI size_t __strxfrm(char* __dest, const char* __src, s
   return ::_strxfrm_l(__dest, __src, __n, __loc);
 }
 
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+#if _LIBCPP_HAS_WIDE_CHARACTERS
 inline _LIBCPP_HIDE_FROM_ABI int __iswctype(wint_t __c, wctype_t __type, __locale_t __loc) {
   return ::_iswctype_l(__c, __type, __loc);
 }
@@ -240,7 +240,7 @@ inline _LIBCPP_HIDE_FROM_ABI int __wcscoll(const wchar_t* __ws1, const wchar_t*
 inline _LIBCPP_HIDE_FROM_ABI size_t __wcsxfrm(wchar_t* __dest, const wchar_t* __src, size_t __n, __locale_t __loc) {
   return ::_wcsxfrm_l(__dest, __src, __n, __loc);
 }
-#endif // !_LIBCPP_HAS_NO_WIDE_CHARACTERS
+#endif // _LIBCPP_HAS_WIDE_CHARACTERS
 
 #if defined(__MINGW32__) && __MSVCRT_VERSION__ < 0x0800
 _LIBCPP_EXPORTED_FROM_ABI size_t __strftime(char*, size_t, const char*, const struct tm*, __locale_t);