<Swing Dev> [13] RFR 8196096: javax/swing/JPopupMenu/6580930/bug6580930.java fails

[semyon.sadetsky at oracle.com]

JBS: https://bugs.openjdk.java.net/browse/JDK-8196096

webrev: http://cr.openjdk.java.net/~ssadetsky/8196096/webrev.00/

This is a fix for an unstable test:

- inside EDT execution is ensured where necessary.

- To pass on the mac platform the check for lightweight popup is 
excluded and the taskbar overlapping Swing property is enabled.


--Semyon