[code-reflection] Integrated: Post OpWrapper cleanup, removed some experiments and fixed Violajones…

[Gary Frost]

Another post Opwrapper cleanup. 

Also removed some dead experiments.

Patched Violajones example, where we had incorrect buffer access annotation on rgbToGrey kernel

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Commit messages:
 - Post OpWrapper cleanup, removed some experiments and fixed Violajones buffer accesses

Changes: https://git.openjdk.org/babylon/pull/547/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=547&range=00
  Stats: 1114 lines in 12 files changed: 11 ins; 1064 del; 39 mod
  Patch: https://git.openjdk.org/babylon/pull/547.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/547/head:pull/547

PR: https://git.openjdk.org/babylon/pull/547