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

[musl] / src / thread / __wake.c

#include "pthread_impl.h"

void __wake(volatile int *addr, int cnt, int priv)
{
        if (priv) priv = 128; priv=0;
        if (cnt<0) cnt = INT_MAX;
        __syscall(SYS_futex, (long)addr, FUTEX_WAKE | priv, cnt);
}