[code-reflection] Integrated: fix std::string to char * for kernel names

[Gary Frost]

Opencl and PTX backends now aligned with CUDA

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Commit messages:
 - fix std::string to char * for kernel names

Changes: https://git.openjdk.org/babylon/pull/106/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=106&range=00
  Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/babylon/pull/106.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/106/head:pull/106

PR: https://git.openjdk.org/babylon/pull/106