Auto-sync with upstream branch master
    
    Upstream commit 464cd3a9d5f505d92bae9a941bb75b0d91ac14ee
    
    - y2038: Introduce struct __timespec64 - new internal glibc type
    - auto-changelog: Remove latin1 from codecs
    - Set the expects flags to clock_nanosleep
    - Fix tst-sigcontext-get_pc rule name from a43565ac447b1
    - inet/net-internal.h: Fix uninitalised clntudp_call() variable
    - Fix vDSO initialization on arm and mips
    - Script to generate ChangeLog-like output from git log
    - [powerpc] SET_RESTORE_ROUND optimizations and bug fix
    - Fix building support_ptrace.c on i686-gnu.
    - S390: Use _HP_TIMING_S390_H instead of _HP_TIMING_H.
    - Update syscall-names.list for Linux 5.3.
    - Use Linux 5.3 in build-many-glibcs.py.
    - S390: Add support for HP_TIMING_NOW.
    - Fix RISC-V vfork build with Linux 5.3 kernel headers.
    - Add UNSUPPORTED check in elf/tst-pldd.
    - sparc64: Use linux generic time implementation
    - mips: Consolidate INTERNAL_VSYSCALL_CALL
    - powerpc: Simplify vsyscall internal macros
    - Refactor vDSO initialization code
    - Remove PREPARE_VERSION and PREPARE_VERSION_KNOW
    - Fix small error in HP_TIMING_PRINT trailing null char setting