Send + Sync is not implemented for iOS proxy

[jkelleyrtp]

On mac, windows, and linux, the proxy type has an unsafe impl so the proxy can be shared across threads

pub struct Proxy<T> {
  sender: Sender<T>,
  source: CFRunLoopSourceRef,
}

unsafe impl<T: Send> Send for Proxy<T> {}
unsafe impl<T: Send> Sync for Proxy<T> {}

But this does not exist for iOS.

I have to hack around this limitation by doing these impls myself. It'd be great if this was just built in.

[amrbashir]

I think it is probably safe to implement Sync for it but I am not sure since I can't test it, however, Send is implemented for the proxy on iOS

tao/src/platform_impl/ios/event_loop.rs

Lines 164 to 169 in b3aa398

	pub struct EventLoopProxy<T> {
	sender: Sender<T>,
	source: CFRunLoopSourceRef,
	}
	unsafe impl<T: Send> Send for EventLoopProxy<T> {}

Shouldn't that be enough? like you can create a new proxy and just send it to the thread instead of sending a reference.