[code-reflection] Integrated: Hat move javac and java opts from job builder

[Gary Frost]

Previously the job.jar builder hardcoded the javac opts and also push java runtime opts 

Now these are where they should have been.  In the `hat.java` script. 

We should now also be able to pass -Dfoo=bar properties and even trailing app/test args in a uniform way.

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Commit messages:
 - Moved handling of javac and java opts up to hat.java
 - added a nbody vector kernel

Changes: https://git.openjdk.org/babylon/pull/702/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=702&range=00
  Stats: 248 lines in 9 files changed: 187 ins; 13 del; 48 mod
  Patch: https://git.openjdk.org/babylon/pull/702.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/702/head:pull/702

PR: https://git.openjdk.org/babylon/pull/702