Fcemu don't support zapper mode on touchscreen.

[Icy-Veins]

I tested some games that need to use zapper mode. I turned on fceumm_zapper_mode-touchscreen, fceumm_show_crosshair-enabled and set the controller to Zapper mode. I saw that the cursor moved with the finger on the screen, but the click did not work.

[Swordfish90]

I'm able to reproduce the issue. I think the "fire" signal is not sent to the libretro core.