y2038: nptl: Convert pthread_{clock|timed}join_np to support 64 bit time

The pthread_clockjoin_np and pthread_timedjoin_np have been converted to
support 64 bit time.

This change introduces new futex_timed_wait_cancel64 function in
./sysdeps/nptl/futex-internal.h, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_{timed|clock}join_np only accept absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
clockwait_tid() always passes struct __timespec64.

For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_{clock|timed}join_np64 will provide support
  for 64 bit time

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_{timed|clock}join_np64 and
__pthread_{timed|clock}join_np.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

nptl/pthread_clockjoin.c

@@ -16,14 +16,27 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <time.h>
 #include "pthreadP.h"
 
 int
-__pthread_clockjoin_np (pthread_t threadid, void **thread_return,
-			clockid_t clockid,
-			const struct timespec *abstime)
+__pthread_clockjoin_np64 (pthread_t threadid, void **thread_return,
+                          clockid_t clockid, const struct __timespec64 *abstime)
 {
   return __pthread_clockjoin_ex (threadid, thread_return,
                                  clockid, abstime, true);
 }
+
+#if __TIMESIZE != 64
+libc_hidden_def (__pthread_clockjoin_np64)
+
+int
+__pthread_clockjoin_np (pthread_t threadid, void **thread_return,
+                        clockid_t clockid, const struct timespec *abstime)
+{
+  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
+
+  return __pthread_clockjoin_np64 (threadid, thread_return, clockid, &ts64);
+}
+#endif
 weak_alias (__pthread_clockjoin_np, pthread_clockjoin_np)