What's the current status of WASM/WASI support?

[ChrisG]

In 2019, there was a blog post that indicated a strong push for 
wasm support was afoot. I've had a hard time pulling together 
information since then. I was curious if anyone has a good 
general perspective on the state of D wasm support. I can't tell 
if it's a mostly dead subject. It looks like betterC support is 
generally there, but I'm not sure about runtime or library 
support. Specifically, I was interested in:

- What's the runtime support story (can I use GC)?
- What's the phobos support story?
- Are there alternate general purpose libraries folks have 
settled on for wasm development? (spasm?)
- Anything about WASI or Emscripten?

Thanks.