math: raise flags in log2l.c on <= 0 arguments, and fix volatile

[musl] / src / complex / csinf.c

#include "libm.h"

float complex csinf(float complex z)
{
        z = csinhf(cpackf(-cimagf(z), crealf(z)));
        return cpackf(cimagf(z), -crealf(z));
}