8296087: Problem list headful tests which may fail on Linux VMs

Reviewed-by: jdv

Author: prrace

test/jdk/ProblemList.txt

@@ -650,6 +650,8 @@ javax/swing/JWindow/ShapedAndTranslucentWindows/TranslucentJComboBox.java 802462
 # The next test below is an intermittent failure
 javax/swing/JTree/DnD/LastNodeLowerHalfDrop.java 8159131 linux-all
 javax/swing/JTree/4633594/JTreeFocusTest.java 7105441 macosx-all
+javax/swing/JTree/6263446/bug6263446.java 8296083 linux-all
+javax/swing/JSpinner/4788637/bug4788637.java 8296084 linux-all
 javax/swing/AbstractButton/6711682/bug6711682.java 8060765 windows-all,macosx-all
 javax/swing/JFileChooser/6396844/TwentyThousandTest.java 8198003 generic-all
 javax/swing/JPopupMenu/6800513/bug6800513.java 7184956 macosx-all