[code-reflection] Integrated: Moved C99 kernel specific building to KernelCodeBuilder

[Gary Frost]

I realized we did not need one level of C99CodeBuilder. So we now have one less. 

Also moved C99 kernel specific code to the HATKernelBuilder (this code was in the base class used by Compute layer)

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Commit messages:
 - Moved C99 kernel specific building to KernelCodeBuilder

Changes: https://git.openjdk.org/babylon/pull/818/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=818&range=00
  Stats: 332 lines in 5 files changed: 144 ins; 181 del; 7 mod
  Patch: https://git.openjdk.org/babylon/pull/818.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/818/head:pull/818

PR: https://git.openjdk.org/babylon/pull/818