cd_poly_find_roots

Zero leading coefficients give roots at infinity (set to $2^{1023}(1 + i)$) and zero trailing coefficients roots at zero. At most maxiter iterations are done; the iteration stops when $d - 1$ times the largest relative step is below reltol, where $d$ is the number of finite nonzero roots, or when the step is below $2^{-50}$. Each step is limited to an absolute size between $2^{-10}$ and $2^{-3}$, adapted to the progress (the callers scale the polynomial so that the roots have modulus near 1), and roots of modulus greater than 1 are updated through the reversed polynomial to avoid overflow. The output is sorted.