(FUTEX_PRIVATE_FLAG,

(FUTEX_PRIVATE_FLAG,
LLL_PRIVATE, LLL_SHARED, __lll_private_flag): Define.
(lll_futex_wait): Add private argument, define as wrapper around
lll_futex_timed_wait.
(lll_futex_timed_wait, lll_futex_wake): Add private argument,
use __lll_private_flag macro.
(lll_robust_mutex_dead, __lll_mutex_unlock, __lll_robust_mutex_unlock,
__lll_mutex_unlock_force): Pass LLL_SHARED as last arg to lll_futex_*.