I would love to get WASM running. I did a little bit with it, but nothing really usable. I came across this gist https://github.com/crystal-lang/crystal/issues/829#issuecomment-599596803 that shows. My guess is if you compile crystal with LLVM10, and maybe a few flags, then you might be able to get away with it using the wasm target triple.
With that said, I have no clue what I’m doing, so I could also be talking gibberish lol. If you happen to understand any of this, or manage to get anything going, report back!