Bedrock2 v0.0.4

A pre-release tag for use with Fiat Cryptography v0.0.16 and a non-dev opam package.

What's Changed (Partial List)

• use vm_compute instead of Ltac to check instruction bounds
• Pass -native-compiler ondemand for bedrock2 ex by @JasonGross in #283
• trying to merge egraph-less parts from egraphs branch by @samuelgruetter in #284

Full Changelog: v0.0.3...v0.0.4