[code-reflection] Integrated: Added some hat tooling from my secret stash

[Gary Frost]

I have collected a bunch of tooling which I have used to analyse code models.  

I figured it was time to check them in, in case anyone else finds them useful. 

I will add a doc showing how to use them a little later.

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Commit messages:
 - Added some hat tooling from my secret stash

Changes: https://git.openjdk.org/babylon/pull/498/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=498&range=00
  Stats: 5216 lines in 73 files changed: 4749 ins; 458 del; 9 mod
  Patch: https://git.openjdk.org/babylon/pull/498.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/498/head:pull/498

PR: https://git.openjdk.org/babylon/pull/498