Auto-sync with upstream branch master
    
    Upstream commit: 7b36d26b22d147ffc347f427f9fd584700578a94
    
    - compat getdents64: Use correct offset for retry (swbz#23972)
    - x86: Fix static analysis warning in tst-cet-property-2 (swbz#23490)
    - malloc: Add another test for tcache double free check (swbz#23907)
    - getcpu: New system call wrapper
    - posix_spawn_file_actions_addfchdir_np: New function (swbz#17405)
    - Preparations for the IBM long double transition
    - Preparations for 64-bit time_t on 32-bit architectures
    - Enable VDSO for static linking on arm (swbz#19767)