Previously, pthread_mutexattr_gettype() and
pthread_mutexattr_settype() were non-conformant and also
less safe, as they would not check whether a pthread_mutexattr_t
had been initialized prior to manipulating them. Furthermore,
they would potentially dereference NULL pointers.
Additionally, move the pthread_mutexattr_init() and
pthread_mutexattr_destroy() functions to the library, and add
some level of checking to them so that they are more than simply
static inline / no-op calls.
Lastly, reduce the size of struct pthread_mutexattr to only
what is necessary (one byte should suffice).
Signed-off-by: Christopher Friedt <cfriedt@meta.com>
ec27e8875d