moving jtreg forward

[Jonathan Gibbons]

Sean, Rob,

We're looking at advancing jtreg so that it will require JDK 8 (or 
better) to run jtreg itself, although it will still be able to test as 
far back as we want to go -- meaning JDK 5 or so.  For refer4ence, jtreg 
currently only requires JDK 5 or better.

One consequence is that we would not be able to use -samevm mode for 
anything less than JDK 8, but -agentvm should provide a satisfactory 
replacement.

Do you see any problems from the Sustaining side of the organization if 
we require JDK 8 or better to be used to run jtreg?

-- Jon