b691770faa
This change adds SourceLoc information per instruction in a `VCode<Inst>` container, and keeps this information up-to-date across register allocation and branch reordering. The information is initially collected during instruction lowering, eventually collected on the MachSection, and finally provided to the environment that wraps the codegen crate for wasmtime.
This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.