[jdk21u] RFR: 8309778: java/nio/file/Files/CopyAndMove.java fails when using second test directory

[Goetz Lindenmaier]

I backport this for parity with 17.0.10-oracle.  21u should not fall back.

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Commit messages:
 - Backport cfae6ef2f61f0a6611de2f66e6e773c547ba7878

Changes: https://git.openjdk.org/jdk21u/pull/306/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=306&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309778
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u/pull/306.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/306/head:pull/306

PR: https://git.openjdk.org/jdk21u/pull/306