RFR: 8340143: Open source several Java2D rendering loop tests.

[Phil Race]

Open source some Java2d loop rendering tests.

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Commit messages:
 - 8340143

Changes: https://git.openjdk.org/jdk/pull/21114/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21114&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340143
  Stats: 394 lines in 5 files changed: 394 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21114.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21114/head:pull/21114

PR: https://git.openjdk.org/jdk/pull/21114