7022382: convert pack200 library code to use try-with-resources Reviewed-by: ksrini

5045147: Prevent insertion of null Key into empty TreeMap (and null element into TreeSet) when no Comparator is used. Prevent insertion of key of incorrect type into empty TreeMap and incorrect type element into TreeSet and incorrect type when Comparator is used. Reviewed-by: alanb, dl, mduigou

Merge

7028133: Specify serialVersionUID for RegularEnumSet and JumboEnumSet Reviewed-by: alanb, mduigou Contributed-by: Neil Richards <neil.richards@ngmr.net>