RFR: 8006164 [TESTBUG] compact profile hotspot test issues

[David Holmes]

This change introduces the TEST.groups file to allow jtreg to run 
regression tests by groups - where the groups are defined to support 
testing of compact profiles and the minimal VM.

webrev: http://cr.openjdk.java.net/~dholmes/8006164/webrev/

The primary groups are:
  - jdk
  - jre
  - compact3
  - compact2
  - compact2_minimal
  - compact1
  - compact1_minimal

The minimal VM is only supported on compact1 and compact2.

To select a group of tests you use :<group-name>

Eg to run only those tests that can run on compact1 use:

jtreg :compact1

Of course you still need to point jtreg at the right kind of runtime 
image (and give it a full JDK as the compile-jdk!); and if testing the 
minimal VM you need to tell jtreg to select it using -javaoptions:-minimal

The full jtreg group facility is only available in the most recent jtreg 
builds, so you will need to grab the latest nightly build, or latest 
sources.

It is expected that these group definitions will need some tweaking. So 
far testing has been limited to linux, but we want to get this in ASAP 
to extend the testing.

Note: once this is in place, anyone writing regression tests will need 
to be aware of whether that test is limited to certain profiles and 
update the group file accordingly. Sometimes it is not the item being 
tested that determines the minimum needed profile, but the test 
infrastructure eg if it uses XML.

The changeset will be pushed via hotspot-embas that is what is used for 
profile testing.

Thanks,
David