JavaScript virtual machine with QuickJS running in WASM under Go/JS

This uses a "reactor" mode I added to quickjs recently which exposes quickjs as a wasi library instead of a traditional main() loop. This allows the host environment to call loop_once() to step once through the JS event loop, and poll_io() to check for I/O. This way, if there's nothing available to do (VM is idle), the Go host environment (or js) can sleep until some I/O arrives. This is a lot more efficient than having Js poll for I/O.

Check it out: https://github.com/aperturerobotics/go-quickjs-wasi-reactor