Auto-sync with upstream branch master
    
    Upstream commit: 0be0845b7a674dbfb996f66cd03d675f0f6028dc
    
    - S390: Regenerate ULPs.
    - manual: Fix sigdescr_np and sigabbrev_np return type (BZ #26343)
    - math: Update x86_64 ulps
    - math: Regenerate auto-libm-test-out-j0
    - manual: Put the istrerrorname_np and strerrordesc_np return type in braces
    - Linux: Use faccessat2 to implement faccessat (bug 18683)
    - manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)
    - math: Fix inaccuracy of j0f for x >= 2^127 when sin(x)+cos(x) is tiny
    - Update syscall lists for Linux 5.8.
    - Use Linux 5.8 in build-many-glibcs.py.
    - htl: Enable tst-cancelx?[45]
    - tst-cancel4: Make blocking on write more portable
    - hurd: Add missing hidden def
    - hurd: Rework sbrk
    - hurd: Implement basic sched_get/setscheduler
    - x86: Rename Intel CPU feature names
    - manual: Fix some @code/@var formatting glitches chapter Date And Time
    - Copy regex_internal.h from Gnulib
    - Copy regex BITSET_WORD_BITS porting from Gnulib
    - Sync regex.h from Gnulib
    - Sync mktime.c from Gnulib
    - Sync intprops.h from Gnulib
    - Open master branch for glibc 2.33 development.