RFR (XXS) : 8153516: Hotspot TEST.group has error in GC groups definition.

[Michail Chernov]

Hi

Could I have a review for this small change in TEST.groups which fixes 
GC tests groups, please?

https://bugs.openjdk.java.net/browse/JDK-8153516
http://cr.openjdk.java.net/~mchernov/8153516/webrev.00/

Latest changes added and renamed existing groups from hotspot_gc to 
hotspot_fast_gc_1 and hotspot_fast_gc_2, however hostpot_jprt uses 
hotspot_fast_gc group which is undefined. This fix changes it.

Tested locally by executing 'jprt' -l to get list of tests. All groups 
work as expected.

Thanks
Michail