Interpolation doesn't work for non-integral domains

[wbhart]

Is it possible to interpolate over a non-integral domain? The current implementation doesn't work, though raises an impossible inverse error for now.

[fredrik-johansson]

Polynomial interpolation is the same thing as solving the linear system (Vandermonde matrix) * (coefficients) = (values), so it could be done by falling back on linear solving for non-integral domains.