[lworld] Integrated: 8294774: add more regression tests for value objects

[Vicente Romero]

additional test coverage for value objects

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Commit messages:
 - adding tests for compiler keys in the not-yet file
 - updating compiler error key
 - 8294774: add more regression tests for value objects

Changes: https://git.openjdk.org/valhalla/pull/777/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=777&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294774
  Stats: 559 lines in 20 files changed: 469 ins; 37 del; 53 mod
  Patch: https://git.openjdk.org/valhalla/pull/777.diff
  Fetch: git fetch https://git.openjdk.org/valhalla pull/777/head:pull/777

PR: https://git.openjdk.org/valhalla/pull/777