[lworld] RFR: 8292942: [lworld] add a test to check that an anonymous class is always an identity class

[Vicente Romero]

This PR is adding some regression tests to make sure that anonymous classes are identity classes

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Commit messages:
 - 8292942: [lworld] add a test to check that an anonymous class is always an identity class

Changes: https://git.openjdk.org/valhalla/pull/741/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=741&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292942
  Stats: 65 lines in 1 file changed: 41 ins; 22 del; 2 mod
  Patch: https://git.openjdk.org/valhalla/pull/741.diff
  Fetch: git fetch https://git.openjdk.org/valhalla pull/741/head:pull/741

PR: https://git.openjdk.org/valhalla/pull/741