Fix wasm-bindgen initialization function warning

[Destructor17]

I've had to fork wasm_thread to add some specific features like async entrypoint and post_message. I hope to upstream these changes later, but first things first.

JS shim initialization function generated by new versions of wasm-bindgen now looks like this:

async function __wbg_init(module_or_path, memory) {
    ...
    if (Object.getPrototypeOf(module_or_path) === Object.prototype) {
        ({module_or_path, memory, thread_stack_size} = module_or_path)
    } else {
        console.warn('using deprecated parameters for the initialization function; pass a single object instead')
    }
    ...

It excepts both module and memory to be passed using one object (see diff), otherwise logs a warning.

This PR also contains some changes my IDE did without asking me, but I guess it's for good.