- update to version 2.72
* Support for ensuring time_t is Y2038-safe
configure can now ensure that time_t can represent moments in time
after 18 January 2038, i.e. 2**31 - 1 seconds after the Unix epoch.
On most 64-bit systems this is true by default; the new feature
is detection of systems where time_t is a 32-bit signed integer by
default, *and* there is an alternative mode in which it is larger,
in which case that mode will be enabled.
* AC_USE_SYSTEM_EXTENSIONS now enables C23 Annex F extensions
by defining __STDC_WANT_IEC_60559_EXT__.
* Configure scripts no longer support pre-1989 C compilers.
* Autoconf developers now need Perl 5.10 (2007) or later.
* Autoconf users now need GNU M4 1.4.8 (2006) or later.
* Some m4sh diversions have been renumbered.
* AC_FUNC_GETGROUPS and AC_TYPE_GETGROUPS no longer run test programs.
* All internal uses of AC_EGREP_CPP and AC_EGREP_HEADER have been removed.
- Update dependencies as recommendd to m4 1.4.16, Perl 5.10
- Drop patch autoreconf-ltdl.diff as similar code is part of upstream
- Drop patch fix-testsuite-failures-with-bash-5.2.patch, it is
part of upstream