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

[musl] / src / process / posix_spawnattr_getflags.c

#include <spawn.h>

int posix_spawnattr_getflags(const posix_spawnattr_t *attr, short *flags)
{
        *flags = attr->__flags;
        return 0;
}