[WIP] RISC-U sketch code for Lasso (following Jolt)

RISC-U is a subset of RV64I, see https://github.com/cksystemsteaching/selfie/blob/main/riscu.md

This project will contain an implementation of a RISC-U emulator along with a RISC-U zk circuit simulator using the constraints and lookups defined in the Jolt paper.

The aim of this project is to serve as a reference to implement Jolt.

References

• Lasso: https://people.cs.georgetown.edu/jthaler/Lasso-paper.pdf
• Jolt: https://people.cs.georgetown.edu/jthaler/Jolt-paper.pdf
• Selfie: https://github.com/cksystemsteaching/selfie