RFR: JDK-8151726: Introduce a JPRT testset buildinfra

[Tim Bell]

Erik:

> When verifying build changes, we are currently lacking a good way of 
> doing all relevant builds in one JPRT job. Some build configurations 
> we aren't even able to test at all. To facilitate this, I would like 
> to introduce a new testset. This testset will be a super set of the 
> current default testset and hotspot and then some more.
>
> This patch also adds a bunch of Jib profiles to support these build 
> configurations. The most important for developers is that all main 
> platforms now have a Jib profile for slowdebug.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8151726
> Webrev: http://cr.openjdk.java.net/~erikj/8151726/webrev.01/


Looks good.

/Tim