RFR (S): 8067868: Add GCOld as a JTreg test

Hi everyone, Could I have a couple of reviews for this change to make GCOld a JTreg test? Root repo changes: http://cr.openjdk.java.net/~brutisso/8067868/root-webrev.00/ HotSpot repo changes: http://cr.openjdk.java.net/~brutisso/8067868/hotspot-webrev.00/ Bug report: https://bugs.openjdk.java.net/browse/JDK-8067868 Thanks, Bengt