PlatformImpl in javafx.graphics uses setAccessible to access method in javafx.swing

PlatformImpl.invokeSwingFXUtilsMethod uses setAccessible to call private methods SwingFXUtils.installFwEventQueue and SwingFXUtils.removeFwEventQueue.

Note that since the methods being called are in a public class of a publicly exported package, we cannot just make them public. We do not want to expose this implementation detail as API.