This internal xinput PDO is an HID compatible pass-through device, but
it needs to be kept private and is listed on the internal WINEXINPUT
device interface class, instead of the HID device interface class.

This is a Wine extension for convenience and native XInput driver uses a
different, undocumented, device interface.

We now filter the report read requests to make sure only one is sent
through to the lower bus device, and we complete both gamepad and xinput
read requests at once using the returned data.
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>