csqrt
double complex csqrt(double complex);
PROTO_NORMAL(csqrt);
w = clog(z + csqrt(z + 1) * csqrt(z - 1));
z2 = csqrt (zz);
DEF_STD(csqrt);
LDBL_MAYBE_CLONE(csqrt);
ATF_TC_WITHOUT_HEAD(csqrt);
ATF_TC_BODY(csqrt, tc)
ATF_TP_ADD_TC(tp, csqrt);
return (csqrt((double complex)d));