[jdk17u-dev] RFR: 8315883: Open source several Swing JToolbar tests

[Goetz Lindenmaier]

I backport this for parity with 17.0.15-oracle.

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Commit messages:
 - Backport 62c0a1b9ac6462233f3ee06af470be9844e9e226

Changes: https://git.openjdk.org/jdk17u-dev/pull/3155/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3155&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315883
  Stats: 199 lines in 4 files changed: 199 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3155.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3155/head:pull/3155

PR: https://git.openjdk.org/jdk17u-dev/pull/3155