Latest Firefox?
Not sure if it will be helpful...
https://github.com/cpitclaudel/z3.wasm/blob/2dabbdff0e151cf19b2146d259101d7fe7a1...
hrm, those links are just the index.js.
I actually don't know much about HTML5 as I exported from godot. Made a ticket for it:
https://github.com/mathew-tran/IdleCity/issues/74