Auto-sync with upstream branch master
    
    Upstream commit: 734c60ebb607086ad6d67b2544d6b7baba72a652
    
    - login: Move libutil into libc
    - login: Rework hidden prototypes for __setutent, __utmpname, __endutent
    - login: Hidden prototypes for _getpt, __ptsname_r, grantpt, unlockpt
    - nptl_db: Re-use the ELF-to-abilist converter for ABI checking
    - Add RFC 8335 Definitions from Linux 5.13
    - nss: Fix NSS_DECLARE_MODULE_FUNCTIONS handling of _nss_*_endnetgrent
    - s390x: Update math: redirect roundeven function
    - posix: Add _Fork [BZ #4737]