(Input) Lightgun as Joystick

The option for controlling a lightgun gun game on retroarch is limited to mouse or lightgun.

Please add another input option that gives the ability to map a joystick axis to also be used as a lightgun input. This will need be be mapped as the whole axis e.g. x axis, y axis and not how retroarch currently maps input with x-left, x-right, y-up, y-down.

This will allow multiplayer lightgun games instead of having a single mouse input.

This is currently possible in stand alone emulators such as Mednafen, Supermodel, Teknoparrot, Mame (including retroarch Mame, but configured inside the core) and possibly others. These emulators allow the binding of a joystick axis to allow the lightgun cursor to be positioned anywhere on screen by holding a joystick in any position. Demulshooter also retroactively adds this feature into other emulators that do not support this feature.
These emulators all work great with a wiimote and dolphinbar which makes the ir pointer the z and zr axis.

For your consideration.

No file or test is named. Start by locating RetroArch's lightgun input configuration and current x-left, x-right, y-up, and y-down mapping; done means whole joystick axes can be bound as lightgun input and support multiplayer lightgun games.