Cancel all pending asynchronous socket I/O on Windows upon deinit().

[lithdew]

On Windows, Socket.call() is responsible for driving the asynchronous execution of a socket I/O syscall.

What needs to be done is that prior to the execution of a syscall, an async frame should be queued to an atomic queue of frames stored in a Socket. Upon executing Socket.deinit(), all frames should be forcibly resumed with a flag that would cause error.OperationCancelled to be returned by Socket.call().