RFR: 8306718: Optimize and opensource some old AWT tests

[Alexander Zuev]

Four tests are cleaned and optimized, ready to open source.

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Commit messages:
 - 8306718: Optimize and opensource some old AWT tests

Changes: https://git.openjdk.org/jdk/pull/13637/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13637&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306718
  Stats: 410 lines in 4 files changed: 410 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13637.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13637/head:pull/13637

PR: https://git.openjdk.org/jdk/pull/13637