sysdeps/linux: Add SYS_futex
#define SYS_umount2 166
#define SYS_reboot 169
#define SYS_sethostname 170
+#define SYS_futex 202
#define SYS_getdents64 217
#define SYS_sys_futex 202
#define SYS_fadvise64 221
