viosock overlapped IO/IOCP

[jdkuki]

Is your feature request related to a problem? Please describe.
Overlapped IO is not supported in windows viosocket driver
https://github.com/virtio-win/kvm-guest-drivers-windows/blob/master/viosock/lib/viosocklib.c#L439

Describe the solution you'd like
We are looking to implement bindings to vsock in golang and were hoping to extend the native pattern of using IOCP to handle async IO. IOCP is built off of overlapped IO which we found to not be supported in the guest driver. It would be nice to have this supported in the guest driver as an option for async io.

Describe alternatives you've considered
Looking to implement this using select() as that path appears to be supported in the driver however we are getting a BSOD when trying to prototype (investigating further).

[YanVugenfirer]

@MartinDrab FYI