[macosx] Mnemonic doesn't work in JTabbedPane

Regression. Last times work in b226.

See regression test javax/swing/JTabbedPane/4624207/bug4624207.java
To reproduce the issue run the code and press Ctrl+Alt+a:
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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MyKeyTest {

    static JPanel panel;

    public static void main(String[] args) throws Exception {
        SwingUtilities.invokeAndWait(new Runnable() {

            public void run() {
                JFrame frame = new JFrame("Test Frame");
                frame.setSize(300, 200);
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                panel = new JPanel();
                panel.addKeyListener(new KeyAdapter() {

                    @Override
                    public void keyPressed(KeyEvent e) {
                        System.out.println("[key listener]");
                        System.out.println("key code: " + e.getKeyCode());
                        System.out.println("key char: " + e.getKeyChar());
                        System.out.println("key char int: " + (int) e.getKeyChar());
                    }
                });
                frame.getContentPane().add(panel, BorderLayout.CENTER);
                panel.requestFocus();
                frame.setVisible(true);
            }
        });

        SwingUtilities.invokeAndWait(new Runnable() {

            public void run() {
                panel.requestFocus();
            }
        });
    }

}
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The result after pressing Ctrl+Alt+a is:
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[key listener]
key code: 65
key char:
key char int: 1
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The key char is 1 instead of 'a'