This PR adds `Sym.Simp.evalGround`, a simplification procedure for
evaluating ground terms of builtin numeric types. It is designed for
`Sym.simp`.
Key design differences from `Meta.Simp` simprocs:
- Pure value extraction: `getValue?` functions are `OptionT Id` rather
than
`MetaM`, avoiding `whnf` overhead since `Sym` maintains canonical forms
- Specialized predicate lemmas: comparisons use pre-proved lemmas like
`Int.lt_eq_true` applied with `rfl`, avoiding `Decidable` instance
reconstruction at each call site
- Type dispatch via `match_expr`: assumes standard instances, no
synthesis
Supported types: `Nat`, `Int`, `Rat`, `Fin n`, `BitVec n`,
`UInt8/16/32/64`,
`Int8/16/32/64`.
Supported operations: arithmetic (`+`, `-`, `*`, `/`, `%`, `^`), bitwise
(`&&&`, `|||`, `^^^`, `~~~`), shifts (`<<<`, `>>>`), comparisons (`<`,
`≤`,
`>`, `≥`, `=`, `≠`, `∣`), and boolean predicates (`==`, `!=`).
6a87c0e530