[lworld] RFR: 8371726: [lworld] Re-enable verification once JDK-8371716 is solved

[Marc Chevalier]

Simply reverts [JDK-8367245](https://bugs.openjdk.org/browse/JDK-8367245) / 409f56a757145bf59ba17c9975c0dab2c01eef5b
since the real mainline fix [JDK-8371716](https://bugs.openjdk.org/browse/JDK-8371716) / 76e79dbb3eca5589aae6852c8f55adf0759c714e landed in Valhalla with https://github.com/openjdk/valhalla/pull/1843 (merge jdk-27+3).

Thanks,
Marc

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Commit messages:
 - Update copyright
 - Revert "8367245: [lworld] C2 compilation fails with "Missed optimization opportunity in PhaseIterGVN""

Changes: https://git.openjdk.org/valhalla/pull/1861/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1861&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371726
  Stats: 8 lines in 4 files changed: 0 ins; 4 del; 4 mod
  Patch: https://git.openjdk.org/valhalla/pull/1861.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1861/head:pull/1861

PR: https://git.openjdk.org/valhalla/pull/1861