acos.s fix: use the formula acos(x) = atan2(sqrt(1-x),sqrt(1+x))

[musl] / src / thread / pthread_mutexattr_gettype.c

#include "pthread_impl.h"

int pthread_mutexattr_gettype(const pthread_mutexattr_t *a, int *type)
{
        *type = *a & 3;
        return 0;
}