[code-reflection] Integrated: more codegen cleanup

[Gary Frost]

Some minor codegen changes.  

Also includes a CUDA codegen fix that I missed last time out.  Which was incorectly passing ndrange as a kernel arg.

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Commit messages:
 - more codegen cleanup

Changes: https://git.openjdk.org/babylon/pull/563/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=563&range=00
  Stats: 962 lines in 6 files changed: 890 ins; 56 del; 16 mod
  Patch: https://git.openjdk.org/babylon/pull/563.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/563/head:pull/563

PR: https://git.openjdk.org/babylon/pull/563