In the case of CheerpJ the virtual machine itself is pure C++ compiled to WASM, but the JIT-ted code and the objects are pure JS. Garbage collection is natively handled by the browser.
As WASM GC stabilizes we will consider supporting it as well.
Ah, this is an interesting approach. Does JITing over to JS introduce problems with concurrency support though, given the lack of threads in the JS runtime?
As WASM GC stabilizes we will consider supporting it as well.