Feature request: fast pippenger MSM algorithm as in barretenberg

[imeckler]

The barretenberg library implements a version of the pippinger algorithm that combines the two techniques of batch affine operations and the use of a curve-endomorphism (for fields that have a cube root of unity) to obtain a significant speedup on the straightforward implementation of the pippinger algorithm. It would be great if this algorithm were present in arkworks.

[imeckler]

Oh sorry -- saw there is an existing issue and an implementation by @jon-chuang. Reading this, it seems there was a 1.4x - 1.7x improvement.

[weikengchen]

I think we will be following on this recently. I looked at the existing MSM algorithm and had the feeling that it only implements part of the Pippenger, and there is a high likelihood that it can be improved.

By the way, fantastic work in showing the strength of pairing-based SNARK in Kimchi.