GameInput backend for SDL (Gamepad-only for now)

src/core/windows/SDL_xinput.c

@@ -20,6 +20,8 @@
 */
 #include "SDL_internal.h"
 
+#ifndef SDL_JOYSTICK_GAMEINPUT
+
 #include "SDL_xinput.h"
 
 /* Set up for C function definitions, even when using C++ */
@@ -142,3 +144,5 @@ void WIN_UnloadXInputDLL(void)
 #ifdef __cplusplus
 }
 #endif
+
+#endif /* !SDL_JOYSTICK_GAMEINPUT */