nptl: Move pthread_gettattr_np into libc

nptl: Move pthread_gettattr_np into libc

This is part of the libpthread removal project:

    <https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>

Use __getline instead of __getdelim to avoid a localplt failure.
Likewise for __getrlimit/getrlimit.

The abilist updates were performed by:

git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
  | while read x ; do
    echo "GLIBC_2.32 pthread_getattr_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py --only-linux pthread_getattr_np

The private export of __pthread_getaffinity_np is no longer needed, but
the hidden alias still necessary so that the symbol can be exported with
versioned_symbol.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>