It should include all the valid axis defined in defaultJoystickAxes so the size should now be 8
The 2 extra since the previous size (6) is due to the addition of support for HAT_X and HAT_Y axis.
This fix allows the HAT_X+/- and HAT_Y/+- to operate as valid incoming events when mapped to an action (see Keymapper::convertToIncomingEventType())