Log Message:
Update to 4.72

Upstream changes:
4.72 Wed Apr  3 04:56:03 CEST 2019
        - (libeio) if fd 0 is available do not use it for aio_wd, as it
          collides with IO::AIO::CWD.
        - added IO::AIO::memfd_create.
        - correctly include <sys/uio.h> in the vmsplice test.
        - reduce codesize by ~7% on amd64 by declaring more functions
          as noinline.
        - documentation fixes and updates.
        - experimental and undocumented preliminary support for synchronous statx.

4.71 Sun Mar 10 13:09:26 CET 2019
        - due to an error in the linux manpages, the configure tests
          for readahead, sync_file_range, splice etc. failed. This has been fixed.

4.7  Mon Mar  4 11:28:13 CET 2019
        - majorly speed up scandir for the very special case of a non-POSIX
          filesystem that nevertheless reports valid dt_type information.
          The only known filesystem of this type is currently btrfs, which
          didn't get it's act together to implement POSIX semantics in all
          these years, and I am tired of waiting.
        - add IO::AIO::MCL_ONFAULT for mlockall, add IO::AIO::mlockall.
        - neither sys/mkdev.h nor sys/sysmacros.h were included, even when they
          were detected by autoconf.