To help with easy backporting from upstream, convert the additional man-pages tarball (man-pages-additional-20140218.tar.xz) to one or more patch files. Some of the manual pages might be obsolete or could be replaced with backports from upstream.

With the POSIX manual pages removal in RHEL-101595, there is just one upstream tarball left, so glibc-patches-to-git etc. will start working for this package, simplifying future backports.