* Do not call AC_PROG_CC_C99 on autoconf 2.70+
* Replace obsolete AC_TRY_COMPILE with AC_COMPILE_IFELSE
* Update pkg.m4 to pkg-config-0.29
* Update ax_check_compile_flag.m4
* Update ax_pthread.m4
* Update ax_prototype.m4 and introduce ax_prototype_accept.m4
This also moves the accept() checking to libmongoc/FindDependencies.m4, since it is specific to libmongoc.
* PHPC-2272: as_var_copy.m4 is obsolete
PHP 7.4 requires autoconf 2.68+ and AS_VAR_COPY was introduced in 2.64
* Update to libmongoc 1.24.3
* Define constants for POSIX features and extensions used by libmongoc 1.24
This removes old logic to not define _DEFAULT_SOURCE on Windows (technically MinGW or Cygwin). It's not clear whether that was ever necessary; it was introduced in ab44b0cbeb based on upstream work in mongodb/mongo-c-driver@9d2d8b157c, but libmongoc did not utilize the same logic.
In any event, these constants are now defined unconditionally for libmongoc since mongodb/mongo-c-driver@c5206511cd, so this change should restore parity between PHPC's autoconf and libmongoc's CMake configurations.
* Remove obsolete conditional defines for glibc 2.19
It's not clear what purpose this originally served. It dates back to mongodb/mongo-c-driver@50f701ce6a, but PHPC never incorporated the defines into its own CPPFLAGS.
The recent additions to PlatformFlags.m4 should be sufficient.
GitHub's file finder filters out "build/" directories, among others, which can make it difficult to quickly access these files. Also, the "build/" directory doesn't provide much value here, since it only contains "autotools/".
Jeremy Mikola