dix: initialize the XTest sendEventsProc for all devices
XTest requests lets the client specify a device ID, only if none is specified do we fall back to the XTEST special device. As of commit aa407425 input: Add new hook DeviceSendEventsProc for XTEST regular devices are no longer able to send XTest events because they have no sendEventsProc set.
This caused issue #1574 (closed) and the crash was fixed with commit e820030d xtest: Check whether there is a sendEventsProc to call but we still cannot send XTest events through a specific device.
Fix this by defaulting every device to the XTest send function and punting it to the DDX (i.e. Xwayland) to override the devices as necessary.