Issue with recent configure.ac/autoconf update

I've run into an issue running "autoreconf -i" due to a recent change to configure.ac.

My OS is 64-bit Windows, Build environment is Msys2, compiler is MinGW64, autoconf version is 2.69.

With current master, I have to run "autoreconf -i" twice to get the command to complete. At this point configure, make, and make check all complete successfully.

The suggestion to replace AC_CHECK_INCLUDES_DEFAULT with AC_HEADER_STDC (by kruoli on MersenneForum), fixes the issue of "autoreconf -i" stopping with an error message.

With the AC_HEADER_STDC, each of "autoreconf -i", configure, make, and make check all complete successfully in one try.

For reference, here is the error message I see with current master:

/gmp-ecm/git-ecm-master_2023-11-24/ecm-master  
$ autoreconf -i  
libtoolize: putting auxiliary files in `.'.  
libtoolize: copying file `./ltmain.sh'  
libtoolize: putting macros in AC_CONFIG_MACRO_DIR, `m4'.  
libtoolize: copying file `m4/libtool.m4'  
libtoolize: copying file `m4/ltoptions.m4'  
libtoolize: copying file `m4/ltsugar.m4'  
libtoolize: copying file `m4/ltversion.m4'  
libtoolize: copying file `m4/lt~obsolete.m4'  
configure.ac:385: error: possibly undefined macro: AC_CHECK_INCLUDES_DEFAULT  
      If this token and others are legitimate, please use m4_pattern_allow.  
      See the Autoconf documentation.  
autoreconf: /usr/bin/autoconf-2.69 failed with exit status: 1  
  
/gmp-ecm/git-ecm-master_2023-11-24/ecm-master  
$ autoreconf -i  
configure.ac:179: installing './compile'  
configure.ac:9: installing './config.guess'  
configure.ac:9: installing './config.sub'  
configure.ac:8: installing './install-sh'  
configure.ac:8: installing './missing'  
Makefile.am: installing './INSTALL'  
Makefile.am: installing './depcomp'  
  
/gmp-ecm/git-ecm-master_2023-11-24/ecm-master  
$  

At this point, "./configure " proceeds as normal, with only one line showing an issue:

./configure: line 13568: AC_CHECK_INCLUDES_DEFAULT: command not found