Add a module to gnulib to support posix_fallocate()
for macOS and other systems that are missing it.
Apple-specific code is sourced from Mozilla,
and the rest from glibc, both licensed under LGPL.
Signed-off-by: Michael Pratt <mcpratt@pm.me>
Link: https://github.com/openwrt/openwrt/pull/15690
Signed-off-by: Robert Marko <robimarko@gmail.com>
