[code-reflection] Integrated: CUDA backend now compiles at least

[Gary Frost]

CUDA backend now compiles again.  Still buggy. 

I removed PTX backend from cmake build.  CUDA + PTX backends should share 98 % of code. So I will refactor that next.

Then onto implementing 'minimizing buffer' code in CUDA backend.

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Commit messages:
 - CUDA backend now compiles at least

Changes: https://git.openjdk.org/babylon/pull/374/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=374&range=00
  Stats: 376 lines in 8 files changed: 268 ins; 16 del; 92 mod
  Patch: https://git.openjdk.org/babylon/pull/374.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/374/head:pull/374

PR: https://git.openjdk.org/babylon/pull/374