[jdk17u-dev] RFR: 8327137: Add test for ConcurrentModificationException in BasicDirectoryModel

[Andrew Lu]

I backport this for parity with 17.0.12-oracle.

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Commit messages:
 - Backport 9731b1c8b02d957985f4fb40acd93fb67747a9f0

Changes: https://git.openjdk.org/jdk17u-dev/pull/2477/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2477&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327137
  Stats: 273 lines in 1 file changed: 273 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2477.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2477/head:pull/2477

PR: https://git.openjdk.org/jdk17u-dev/pull/2477