The article answers your question, there are at least 6 languages: Java, OCaml, Scala, Kotlin, Scheme, and Dart.

OCaml with wasocaml: https://github.com/OCamlPro/wasocaml

Dart for a long time now.

I'm not familiar with all the implementation details of objects in C#, but the list of issues mixes runtime implementation details (object layouts) that should be fairly low effort to work around with actual language/runtime features (references, finalization).

In general though most regular C# code written today _doesn't directly_ use many of the features mentioned apart from references. Libraries and bindings however do so a lot since f.ex. p/invoke isn't half as braindead as JNI was, but targeting the web should really not bring along all these libraries anyhow.

So, making a MSIL runtime that handles most common C# code would map pretty much 1-1 with Wasm-GC, some features like ref's might need some extra shims to emulate behaviour (or compiler specializations to avoid too bad performance penalties by extra object creation).

Regardless of what penalties,etc goes in, the generated code should be able to be far smaller and far less costly compared to the situation today since they won't have to ship both their own GC and implement everything around that.

Kotlin/WASM is a thing