KEVM Upgrade Path

[ehildenb]

Overall goal: Want to get Maker KLab pointed a relatively recent version of KEVM, get things working (maybe 98% of the proofs), then turn on auto-updates of KEVM.

Inevitable Changes

• [x] Point CI at Kurt's KLab fork.
• [x] Pin a version of Z3. (4.6.0 or 4.8.6).
• [ ] Run makerdao/k-dss with new CI setup (done?).
• [ ] Get regression test merged into KEVM master (with paired down rules file and smt prelude).

Changes we need to actually check for

• [ ] Change the way that memory specs are generated (check with Daejun on that).
• [ ] Use paired down rules file and smt prelude on fork of KLab.
• [ ] Updating to latest KEVM master.
• [ ] Move all lemmas out of KLab to k-dss repo.
• [ ] Use version of KEVM pegged in k-dss repo
• [ ] Auto-update of KEVM submodule of Maker KLab.

[nanexcool]

Pinned z3 to 4.8.7 with @ehildenb blessing ;)