Implement pippenger MSM

[lonerapier]

No description provided.

[0xJepsen]

let me know if you guys want help with this

[Autoparallel]

@lonerapier do any of the new issues capture this? Can you describe this a bit more?

[lonerapier]

I don't think any of the new issues has any intersections with this.

These changes will include everything in ecc/scalar_multiplication module in barretenberg.

[laudiacay]

this is still unimplemented- should I get started on it? (sept 18)

[laudiacay]

@PatStiles and @lonerapier have written part of this, but it doesn't work yet (in #88)

not the most important work ATM but will be good eventually!

i will wait to award this bounty until plonk works to disincentivize yakshaving ;_;