This lets us avoid the cost of `cranelift_codegen::ir::Opcode` to `peepmatic_runtime::Operator` conversion overhead, and paves the way for allowing Peepmatic to support non-clif optimizations (e.g. vcode optimizations). Rather than defining our own `peepmatic::Operator` type like we used to, now the whole `peepmatic` crate is effectively generic over a `TOperator` type parameter. For the Cranelift integration, we use `cranelift_codegen::ir::Opcode` as the concrete type for our `TOperator` type parameter. For testing, we also define a `TestOperator` type, so that we can test Peepmatic code without building all of Cranelift, and we can keep them somewhat isolated from each other. The methods that `peepmatic::Operator` had are now translated into trait bounds on the `TOperator` type. These traits need to be shared between all of `peepmatic`, `peepmatic-runtime`, and `cranelift-codegen`'s Peepmatic integration. Therefore, these new traits live in a new crate: `peepmatic-traits`. This crate acts as a header file of sorts for shared trait/type/macro definitions. Additionally, the `peepmatic-runtime` crate no longer depends on the `peepmatic-macro` procedural macro crate, which should lead to faster build times for Cranelift when it is using pre-built peephole optimizers.
This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.