RFR: 8361587: AssertionError in File.listFiles() when path is empty and -esa is enabled

[Brian Burkhalter]

Changes to address `File.listFiles` invoked on an empty path. This fixes an oversight in #22821.

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Commit messages:
 - 8361587: AssertionError in File.listFiles() when path is empty and -esa is enabled

Changes: https://git.openjdk.org/jdk/pull/26224/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26224&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8361587
  Stats: 24 lines in 3 files changed: 22 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/26224.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26224/head:pull/26224

PR: https://git.openjdk.org/jdk/pull/26224