With the module linking proposal the field name on imports is now optional, and only the module is required to be specified. This commit propagates this API change to the boundary of wasmtime's API, ensuring consumers are aware of what's optional with module linking and what isn't. Note that it's expected that all existing users will either update accordingly or unwrap the result since module linking is presumably disabled.
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.