RFC : 8244614 : cleanup keywords used/available in hotspot testbase

[Igor Ignatyev]

Hi all,

I'm planning to clean up jtreg keywords that we have in test/hotspot/jtreg as most of them seem to be useless, confuse and make people to add these keywords in vain. After looking at how hotspot k/w are used, as well as which k/w are available and used by other test suites, I'd like to propose the following:
 - keep and document 'headful', 'stress' as they are useful for test selection;
 - keep and document 'intermittent', 'randomness' as they bring extra information about tests stability/reproducibility/determinism;
 - remove 'nmt', 'gc', 'metaspace' as they are used only in obvious places and aren't informative;
 - remove 'cte_test' as it's an artifact of old days and doesn't bring any useful information anymore;
 - remove 'jcmd', not all tests which depend on jcmd has this k/w, so it can't be used for test selection/filtering; there is also no obvious reasons to single out jcmd from other binaries bundled w/ JDK
 - remove 'regression' as the usage of at-bug is more common and convey the same meaning; and for two tests which have regression k/w, but don't have at-bug: 
  - mark vmTestbase/nsk/jvmti/RedefineClasses/redefclass031/TestDescription.java w/ at-bug 6318850;
  - don't mark runtime/NMT/ReleaseNoCommit.java as it wasn't integrated as a true regression test, but rather as a function test for NMT w/ bunch of other NMT tests (where aren't marked w/ 'regression' k/w) by JDK-8054952.

I'd like to receive some feedback on the proposed changes before I (more likely sed) remove keywords from 500+ tests and spend time testing that.

[1] is the preliminary webrev just to illustrate the change, it only updates TEST.ROOT file and adds @bug to redefclass031 test.

Thanks,
-- Igor

for reference, k/w available in other test suites:
jdk : 2d dnd headful i18n intermittent printer randomness jfr
langtools: intermittent randomness
jaxp: intermittent randomness

[1] http://cr.openjdk.java.net/~iignatyev//8244614/webrev.00