[wpilib] Add IsJoystickConnected method (#2847)

wpilibc/src/main/native/include/frc/DriverStation.h

@@ -181,6 +181,17 @@ class DriverStation : public ErrorBase {
    */
   int GetJoystickAxisType(int stick, int axis) const;
 
+  /**
+   * Returns if a joystick is connected to the Driver Station.
+   *
+   * This makes a best effort guess by looking at the reported number of axis,
+   * buttons, and POVs attached.
+   *
+   * @param stick The joystick port number
+   * @return true if a joystick is connected
+   */
+  bool IsJoystickConnected(int stick) const;
+
   /**
    * Check if the DS has enabled the robot.
    *