Change order we enumerate Windows joysticks.

Make it so XInput devices are listed before DirectInput devices, and that the XInput
 devices are sorted by userid in ascending numeric order (so device 0 comes first).

src/joystick/windows/SDL_dxjoystick.c

@@ -766,8 +766,10 @@ static void
 EnumXInputDevices(JoyStick_DeviceData **pContext)
 {
     if (s_bXInputEnabled) {
-        Uint8 userid;
-        for (userid = 0; userid < SDL_XINPUT_MAX_DEVICES; userid++) {
+        int iuserid;
+        /* iterate in reverse, so these are in the final list in ascending numeric order. */
+        for (iuserid = SDL_XINPUT_MAX_DEVICES-1; iuserid >= 0; iuserid--) {
+            const Uint8 userid = (Uint8) iuserid;
             XINPUT_CAPABILITIES capabilities;
             if (XINPUTGETCAPABILITIES(userid, XINPUT_FLAG_GAMEPAD, &capabilities) == ERROR_SUCCESS) {
                 /* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
@@ -796,9 +798,6 @@ void SDL_SYS_JoystickDetect()
         pCurList = SYS_Joystick;
         SYS_Joystick = NULL;
 
-        /* Look for XInput devices... */
-        EnumXInputDevices(&pCurList);
-
         /* Look for DirectInput joysticks, wheels, head trackers, gamepads, etc.. */
         IDirectInput8_EnumDevices(dinput,
             DI8DEVCLASS_GAMECTRL,
@@ -809,6 +808,9 @@ void SDL_SYS_JoystickDetect()
         SDL_RawDevList = NULL;
         SDL_RawDevListCount = 0;
 
+        /* Look for XInput devices. Do this last, so they're first in the final list. */
+        EnumXInputDevices(&pCurList);
+
         SDL_UnlockMutex( s_mutexJoyStickEnum );
     }