`al_set_joystick_mappings` can report more buttons/sticks than exist

[connorjclark]

The _AL_JOYSTICK_INFO generated for controllers that exist in the controller database contain every button/stick possible - however, not all controllers support every button or stick.

For example, the 8bitdo micro does not have thumb buttons or a right stick, yet allegro reports that it does.

_al_fill_gamepad_info should somehow skip over buttons/sticks that do not appear in the controller database mapping.

[SiegeLord]

Does it controller otherwise work? You just don't get events for those missing buttons?

[connorjclark]

Yeah it works otherwise, but if for example you want to populate a dropdown list with a selection of available buttons (which is admittedly bad UX) it would be problematic that some buttons aren't real.

In hindsight I actually don't care about this at all. Feel free to close if fixing is too low priority.

[SiegeLord]

I think this is a valid issue. The goal of the joystick rework was to make it possible to have consistent cross-joystick/cross-platform defaults, and adjusting those defaults in response to what is actually present seems reasonable.