Auto-sync with upstream branch release/2.31/master
    
    Upstream commit: c839175267842bd9e20fdb6637c82f2790d3754f
    
    - aarch64: fix strcpy and strnlen for big-endian (swbz#25824)
    - aarch64: Accept PLT calls to __getauxval within libc.so
    - x86-64: Use RDX_LP on __x86_shared_non_temporal_threshold [BZ #25966]
    - oc_FR locale: Fix spelling of April (swbz#25639)
    - oc_FR locale: Fix spelling of Thursday (swbz#25639)
    - Add a C wrapper for prctl (swbz#25896)
    - Add a C wrapper for prctl (swbz#25896)
    - powerpc: Rename argN to _argN in LOADARGS_N (swbz#25902)
    - Add C wrappers for process_vm_readv/process_vm_writev (swbz#25810)
    - Mark unsigned long arguments with U in more syscalls (swbz#25810)
    - Add a syscall test for (swbz#25810)
    - Add SYSCALL_ULONG_ARG_[12] to pass long to syscall (swbz#25810)
    - x32: Properly pass long to syscall (swbz#25810)
    - Fix build with GCC 10 when long double = double.
    - Add new file missed in previous hppa commit.
    - Fix data race in setting function descriptors during lazy binding on hppa.
    - nios2: delete sysdeps/unix/sysv/linux/nios2/kernel-features.h
    - mips: Fix bracktrace result for signal frames
    - stdlib: Move tst-system to tests-container
    - support/shell-container.c: Add builtin kill
    - support/shell-container.c: Add builtin exit
    - support/shell-container.c: Return 127 if execve fails
    - posix: Fix system error return value (swbz#25715)