* src/npth.h [__ANDROID__]: Include <android/api-level.h>
(_NPTH_NO_RWLOCK) [__ANDROID__ && __ANDROID_API__ < 9]: Define.
(npth_rwlockattr_t, npth_rwlockattr_init, npth_rwlockattr_destroy,
npth_rwlockattr_gettype_np, npth_rwlockattr_settype_np,
NPTH_RWLOCK_PREFER_READER_NP, NPTH_RWLOCK_PREFER_WRITER_NP,
NPTH_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP, NPTH_RWLOCK_DEFAULT_NP,
NPTH_RWLOCK_INITIALIZER, NPTH_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP,
NPTH_MUTEX_INITIALIZER, npth_rwlock_t, npth_rwlock_init,
npth_rwlock_destroy, npth_rwlock_tryrdlock, npth_rwlock_rdlock,
npth_rwlock_trywrlock, npth_rwlock_timedrdlock, npth_rwlock_wrlock,
npth_rwlock_rdlock, npth_rwlock_timedwrlock, npth_rwlock_unlock
(_NPTH_NO_RWLOCK): Alternative implementation based on mutex.