693c6ea771
This commit extracts the two implementations of `Compiler` into two separate crates, `wasmtime-cranelfit` and `wasmtime-lightbeam`. The `wasmtime-jit` crate then depends on these two and instantiates them appropriately. The goal here is to start reducing the weight of the `wasmtime-environ` crate, which currently serves as a common set of types between all `wasmtime-*` crates. Long-term I'd like to remove the dependency on Cranelift from `wasmtime-environ`, but that's going to take a lot more work. In the meantime I figure it's a good way to get started by separating out the lightbeam/cranelift function compilers from the `wasmtime-environ` crate. We can continue to iterate on moving things out in the future, too.
This is the wasmtime-environ crate, which contains the implementations
of the ModuleEnvironment and FuncEnvironment traits from
cranelift-wasm. They effectively
implement an ABI for basic wasm compilation that defines how linear memories
are allocated, how indirect calls work, and other details. They can be used
for JITing, native object files, or other purposes.