This commit adds initial (gated) support for the multi-memory wasm proposal. This was actually quite easy since almost all of wasmtime already expected multi-memory to be implemented one day. The only real substantive change is the `memory.copy` intrinsic changes, which now accounts for the source/destination memories possibly being different.
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.