acos.s fix: use the formula acos(x) = atan2(sqrt(1-x),sqrt(1+x))
[musl] / src / thread / x86_64 /
drwxr-xr-x   ..
-rw-r--r-- 387 __set_thread_area.s
-rw-r--r-- 335 __unmapself.s
-rw-r--r-- 395 clone.s
-rw-r--r-- 405 syscall_cp.s