No tsan interceptors for pthread_mutex_clocklock and other new POSIX APIs

[jwakely]

POSIX-1:202x includes several new functions that TSan needs to support:

Austin Group Defect 1216 is applied, adding pthread_cond_clockwait(), pthread_mutex_clocklock(), pthread_rwlock_clockrdlock(), pthread_rwlock_clockwrlock(), and sem_clockwait() to the list of functions that synchronize memory.

(If it matters, pthread_cond_clockwait is required to have cancellation points, and pthread_rwlock_clockwrlock, pthread_rwlock_clockrdlock, and sem_clockwait may have cancellation points.)

Glibc already supports these, and so the following program gives a false positive warning from TSan:

#include <stdio.h>
#include <pthread.h>

pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
struct timespec ts = { 0 };

void* tfunc(void* p)
{
    if (!pthread_mutex_trylock(&m))
    {
        puts("Locked mutex in second thread");
        pthread_mutex_unlock(&m);
    }
    else
        puts("Second thread could not lock mutex");
    return p;
}

int main()
{
    if (!pthread_mutex_clocklock(&m, CLOCK_REALTIME, &ts))
    {
        puts("Locked mutex in main() thread");
        pthread_t thr;
        pthread_create(&thr, 0, tfunc, 0);
        pthread_join(thr, 0);
        pthread_mutex_unlock(&m);
    }
    else
        puts("Failed to lock mutex");
}

==================
WARNING: ThreadSanitizer: unlock of an unlocked mutex (or by a wrong thread) (pid=1)
    #0 pthread_mutex_unlock <null> (libtsan.so.2+0x50241) (BuildId: 4e0d0a71dfb217392f9c0b4e6f757e50fa8e9242)
    #1 main /app/example.c:27 (output.s+0x401287) (BuildId: 06c6ce9eaa9b45a121f91cff2016ac89d2e036dc)

  Location is global 'm' of size 40 at 0x000000404080 (output.s+0x404080)

  Mutex M0 (0x000000404080) created at:
    #0 pthread_mutex_unlock <null> (libtsan.so.2+0x50241) (BuildId: 4e0d0a71dfb217392f9c0b4e6f757e50fa8e9242)
    #1 main /app/example.c:27 (output.s+0x401287) (BuildId: 06c6ce9eaa9b45a121f91cff2016ac89d2e036dc)

SUMMARY: ThreadSanitizer: unlock of an unlocked mutex (or by a wrong thread) (/opt/compiler-explorer/gcc-13.1.0/lib64/libtsan.so.2+0x50241) (BuildId: 4e0d0a71dfb217392f9c0b4e6f757e50fa8e9242) in pthread_mutex_unlock
==================
ThreadSanitizer: reported 1 warnings

A similar false positive is given for any use of functions like std::timed_mutex::try_lock_for with libstdc++, as that uses the new Glibc functions when available.