[code-reflection] RFR: Some OpHelper additions based on vector phase use cases

[Gary Frost]

Spotted some Ophelper opportunities looking at vector phase use cases.

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Commit messages:
 - Some OpHelper additions based on vector phase use cases

Changes: https://git.openjdk.org/babylon/pull/873/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=873&range=00
  Stats: 78 lines in 4 files changed: 36 ins; 8 del; 34 mod
  Patch: https://git.openjdk.org/babylon/pull/873.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/873/head:pull/873

PR: https://git.openjdk.org/babylon/pull/873