This commit introduces initial support for multi-value Wasm. Wasm blocks and calls can now take and return an arbitrary number of values. The encoding for multi-value blocks means that we need to keep the contents of the "Types" section around when translating function bodies. To do this, we introduce a `WasmTypesMap` type that maps the type indices to their parameters and returns, construct it when parsing the "Types" section, and shepherd it through a bunch of functions and methods when translating function bodies.
This crate performs the translation from a wasm module in binary format to the in-memory form of the Cranelift IR.
If you're looking for a complete WebAssembly implementation that uses this library, see Wasmtime.