e659d5cecd
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 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.