[lworld] RFR: 8327213: [lworld] Valhalla runtime testing move to classfile API

[David Simms]

Move from the experimental bytecode API to the classfile API

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Commit messages:
 - 8327213: [lworld] Valhalla runtime testing move to classfile API

Changes: https://git.openjdk.org/valhalla/pull/1030/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1030&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327213
  Stats: 406 lines in 5 files changed: 63 ins; 170 del; 173 mod
  Patch: https://git.openjdk.org/valhalla/pull/1030.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1030/head:pull/1030

PR: https://git.openjdk.org/valhalla/pull/1030