Several of the getKeyStroke methods in KeyStroke.java enumerate the modifiers
like this:

     * The modifiers consist of any combination of:<ul>
     * <li>java.awt.event.InputEvent.SHIFT_MASK (1)
     * <li>java.awt.event.InputEvent.CTRL_MASK (2)
     * <li>java.awt.event.InputEvent.META_MASK (4)
     * <li>java.awt.event.InputEvent.ALT_MASK (8)

Somebody forgot the AltGraph modifier, which has always been included, but not
mentioned in the docs. (It is just another modifier, like shift or meta.)

We should add this line to each method:

     * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK (32)