RFR(S): 8211350: Remove jprt support

[Mikael Vidstedt]

Please review this change which removes support for, and references to, the (Oracle internal) JPRT system.

bug: https://bugs.openjdk.java.net/browse/JDK-8211350
webrev: http://cr.openjdk.java.net/~mikael/webrevs/8211350/webrev.00/open/webrev/

* Background (from the issue)

The Oracle internal JPRT system was once used to build and test the JDK. It has been superseded and can no longer be used to build/test mainline JDK. The support in the JDK code for running jobs in JPRT should be removed.


* About the change

The change touches several areas: build/make, hotspot, and jdk. I’m optimistically sending it out as a single webrev anyway. If it helps, I’m expecting the reviews to roughly map like so:

build-dev: make related files, jprt.*
hotspot-dev: {src,test}/hotspot
core-libs-dev: test/jdk  - I’m especially interested in hearing if the change to test/jdk/tools/lib/tests/Helper.java (to throw if the jmods directory is missing) is valid

Of course I’d welcome reviews across those mappings as well.

* Testing

tier1 (passed), tier2-3 still running (looking good so far).

Cheers,
Mikael