Auto-sync with upstream branch master
    
    Upstream commit: a43c0b5483da4c5e3796af309864cb44256c02db
    
    - x86-64: Create microbenchmark infrastructure for libmvec
    - elf: hidden visibility for __minimal_malloc functions
    - elf: Use a temporary file to generate Makefile fragments [BZ #28550]
    - dso-ordering-test.py: Put all sources in one directory [BZ #28550]
    - elf: Move LAV_CURRENT to link_lavcurrent.h
    - Move assignment out of the CAS condition
    - Add a comment for --enable-initfini-array [BZ #27945]
    - tst-tzset: output reason when creating 4GiB file fails
    - Add LLL_MUTEX_READ_LOCK [BZ #28537]
    - Avoid extra load with CAS in __pthread_mutex_clocklock_common [BZ #28537]
    - Avoid extra load with CAS in __pthread_mutex_lock_full [BZ #28537]
    - String: Split memcpy tests so that parallel build is faster
    - x86: Shrink memcmp-sse4.S code size
    - Support C2X printf %b, %B
    - Update syscall lists for Linux 5.15
    - s390: Use long branches across object boundaries (jgh instead of jh)