[code-reflection] Integrated: Some build fixups after merging hip backend

[Gary Frost]

After merging HIP backend I had to add hip to pom.xml files and to bldr. 

Although at this point we 'skip' the build by default (sadly we need to work out how to stage SPIRV beehive) 

Comments in the `bld` file show how to include hip. For those with appropriate build infra.

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Commit messages:
 - Some build fixups after merging hip backend

Changes: https://git.openjdk.org/babylon/pull/283/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=283&range=00
  Stats: 194 lines in 6 files changed: 47 ins; 95 del; 52 mod
  Patch: https://git.openjdk.org/babylon/pull/283.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/283/head:pull/283

PR: https://git.openjdk.org/babylon/pull/283