Auto-sync with upstream branch master
    
    Upstream commit: 8a814e20d443adc460a1030fa1a66aa9ae817483
    
    - Drop glibc-rh1732406.patch, fix for the regression applied upstream.
    - nptl: Use uintptr_t for address diagnostic in nptl/tst-pthread-getattr
    - Linux: Move getdents64 to <dirent.h>
    - test-container: Install with $(sorted-subdirs) (swbz#24794)
    - gconv: Check reference count in __gconv_release_cache (#1732406)
    - x86-64: Compile branred.c with -mprefer-vector-width=128 (swbz#24603)
    - build-many-glibcs.py: Use Linux 5.2 by default
    - Linux: Use in-tree copy of SO_ constants for !__USE_MISC (swbz#24532)
    - test-container: Avoid copying unintended system libraries