RFR: 8316106: Open source few swing JInternalFrame and JMenuBar tests

[Abhishek Kumar]

Few closed JInternalFrame and JMenuBarswing tests are open sourced.

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Commit messages:
 - Open source few swing JInternalFrame and JMenuBar tests

Changes: https://git.openjdk.org/jdk/pull/15735/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15735&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316106
  Stats: 450 lines in 5 files changed: 450 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15735.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15735/head:pull/15735

PR: https://git.openjdk.org/jdk/pull/15735