Function eval_rot_kernel_prism 

pub fn eval_rot_kernel_prism<F: TwoAdicField>(
    l_skip: usize,
    x: &[F],
    y: &[F],
) -> F

\kappa_\rot(x, y) should equal \delta_{x,rot(y)} on hyperprism.

omega_pows must have length 2^{l_skip}.