Update to 4.79

Upstream changes:
4.79 Sun 25 Sep 2022 18:25:53 CEST
        - the autoconf result of the mount check was not used, so it failed to
          compile on most systems (reported by crackoff@tutanota.com).
        - work around fedora not having a working C compiler setup by design
          (reported by Paul Howarth).

4.78 Tue 06 Sep 2022 12:54:43 CEST
        - add IO::AIO::mount and IO::AIO::umount.
        - add a bunch of symbols from sys/mount.h.

4.77 Mon 05 Sep 2022 02:03:38 CEST
        - add MFD_HUGETLB_2MB and MFD_HUGETLB_1GB constants.
        - add fexecve.
        - add lots of missing functions to @EXPORT_OK.

(wen)