207f60a18e
This commit fully implements outer aliases of the module linking proposal. Outer aliases can now handle multiple-level-up aliases and now properly also handle closed-over-values of modules that are either imported or defined. The structure of `wasmtime::Module` was altered as part of this commit. It is now a compiled module plus two lists of "upvars", or closed over values used when instantiating the module. One list of upvars is compiled artifacts which are submodules that could be used. Another is module values that are injected via outer aliases. Serialization and such have been updated as appropriate to handle this.
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.