ncurses 6.4 - patch 20230114

+ change RV to XR/xr, to avoid conflict with pre-existing usage in vim,
  to use RV/rv to denote DA2 and its response (discussion with Bram
  Moolenaar) -TD
+ add XF flag to xterm+focus so that termcap applications can be aware
  of terminals which may support focus in/out -TD
+ use xterm+focus in xterm-p370 and tmux -TD
+ improve configure-script macros vs compiler warnings.

Author: ThomasDickey

Ada95/aclocal.m4

@@ -29,7 +29,7 @@ dnl***************************************************************************
 dnl
 dnl Author: Thomas E. Dickey
 dnl
-dnl $Id: aclocal.m4,v 1.197 2023/01/07 17:53:15 tom Exp $
+dnl $Id: aclocal.m4,v 1.198 2023/01/11 09:05:23 tom Exp $
 dnl Macros used in NCURSES Ada95 auto-configuration script.
 dnl
 dnl These macros are maintained separately from NCURSES.  The copyright on
@@ -4579,7 +4579,7 @@ AC_DEFUN([CF_UPPER],
 $1=`echo "$2" | sed y%abcdefghijklmnopqrstuvwxyz./-%ABCDEFGHIJKLMNOPQRSTUVWXYZ___%`
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_UTF8_LIB version: 9 updated: 2021/05/19 19:35:25
+dnl CF_UTF8_LIB version: 10 updated: 2023/01/11 04:05:23
 dnl -----------
 dnl Check for multibyte support, and if not found, utf8 compatibility library
 AC_DEFUN([CF_UTF8_LIB],
@@ -4588,8 +4588,7 @@ AC_HAVE_HEADERS(wchar.h)
 AC_CACHE_CHECK(for multibyte character support,cf_cv_utf8_lib,[
 	cf_save_LIBS="$LIBS"
 	AC_TRY_LINK([
-#include <stdlib.h>
-#include <stdio.h>
+$ac_includes_default
 #ifdef HAVE_WCHAR_H
 #include <wchar.h>
 #endif