Include WIT bindings

[Michael-F-Bryan]

This PR updates the wabt embeddings to be in sync with the latest version of wit-bindgen (c047230). I've also included the wapm.toml and README-wapm.md that is present on WAPM.

[Michael-F-Bryan]

The wapm validate command is currently failing because of an InterfaceViolated error... Presumably WASI has changed since the wabt package was released 3 years ago, and now the interfaces = {wasi= "0.0.0-unstable"} line under each [[module]] in wapm.toml needs to be updated.

$ wapm validate .
Error: WASM file "./out/wasi/Debug/wasm-interp" detected as invalid because InterfaceViolated { 
  errors: [
    "Missing import \"wasi_snapshot_preview1\" \"fd_close\"", 
    "Missing import \"wasi_snapshot_preview1\" \"fd_seek\"", 
    "Missing import \"wasi_snapshot_preview1\" \"fd_write\""
  ] 
}

[Michael-F-Bryan]

@syrusakbary can you have a look through this PR to see if I'm doing things right?

I've noticed that running make from the root directory doesn't generate the same folder structure as the wabt package on WAPM. Do I need to do something extra to generate a release build?

[syrusakbary]

We probably want to add the wit-bindings as well?

[Michael-F-Bryan]

I thought commands don't have bindings because they're intended as executables that people run, not libraries that people import?

[syrusakbary]

Packages can have both commands and libraries.

That means, that a package can have 3 CLI binaries (with WASI), and 1 library (with WIT), for example.

So basically, we can have a new libwabt module that has bindings in the package :)

[Michael-F-Bryan]

Oh, that was already added yesterday before marking the PR ready. I'm guessing I forgot to push the code up.

[syrusakbary]

Things look more or less right (to generate libwabt).

I think that to generate the rest of WASI CLI files we need to use cmake (so we need to have that working)

[Michael-F-Bryan]

I think that to generate the rest of WASI CLI files we need to use cmake (so we need to have that working)

Do you mean the executables? The wapm.toml already includes commands for all the executables that you can use at the moment, so I'd say that any further changes to the wabt repo (e.g. modifying CMakeLists.txt to generate new files or build things differently) are out of scope for this project.