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

[musl] / src / thread / pthread_attr_setdetachstate.c

#include "pthread_impl.h"

int pthread_attr_setdetachstate(pthread_attr_t *a, int state)
{
        if (state > 1U) return EINVAL;
        a->_a_detach = state;
        return 0;
}