nptl: Assume __ASSUME_FUTEX_CLOCK_REALTIME support
This patch assumes realtime clock support for nptl and thus removes
all the associated code.
For __pthread_mutex_timedlock the fallback usage for the case where
lll_futex_timed_wait_bitset it not set define is also removed. The
generic lowlevellock-futex.h always define it, so for NPTL code the
check always yield true.
Checked on x86_64-linux-gnu and i686-linux-gnu.
* nptl/nptl-init.c (__have_futex_clock_realtime,
__have_futex_clock_realtime): Remove definition.
(__pthread_initialize_minimal_internal): Remove FUTEX_CLOCK_REALTIME
check test for !__ASSUME_FUTEX_CLOCK_REALTIME.
* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock): Assume
__ASSUME_FUTEX_CLOCK_REALTIME support.
* sysdeps/unix/sysv/linux/i386/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_FUTEX_CLOCK_REALTIME): Remove.
* sysdeps/nptl/lowlevellock-futex.h (lll_futex_timed_wait_bitset):
Adjust comment.