Implemented is_path_owned_by_current_user for wasi.

[Earthmark]

Not that it's doing very much when wasi doesn't have a concept of current user.

For more context:

• Wasi filesystems: https://github.com/WebAssembly/wasi-filesystem/blob/main/wit/types.wit
  • File stat doesn't include a user ID.
• Wasi CLI: https://github.com/WebAssembly/wasi-cli/tree/main/wit
  • I have yet to find any reference to a user.

Emscripten does have a concept of user, so this isn't a valid solution for that target.

This is part of trying to get this to build with wasi as a build target, AKA: #463

This gets gix-sec building for wasi.

[Earthmark]

It turns out the wasm32-unknown-emscripten target already builds successfully for gix-sec.

I don't know if wasm32-unknown-unknown is a valid target, I don't believe that target has a concept of file IO, let alone users.

[Byron]

Thanks a lot!

I think this should work and I have added a (hopefully working) test that will validate that.