[jdk21u-dev] RFR: 8318689: jtreg is confused when folder name is the same as the test name

[Goetz Lindenmaier]

I backport this for parity with 21.0.3-oracle.

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Commit messages:
 - Backport a9b31b587c7487b2222773debde1ce2227884959

Changes: https://git.openjdk.org/jdk21u-dev/pull/87/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=87&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318689
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/87.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/87/head:pull/87

PR: https://git.openjdk.org/jdk21u-dev/pull/87