RFR: 8366254: (fs) UnixException.translateToIOException should translate ELOOP to FileSystemLoopException

[Brian Burkhalter]

Translate a `UnixException` with `errno == ELOOP` to `FileSystemLoopException` instead of the less specific `FileSystemException`.

-------------

Commit messages:
 - 8366254: (fs) UnixException.translateToIOException should translate ELOOP to FileSystemLoopException

Changes: https://git.openjdk.org/jdk/pull/26966/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26966&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366254
  Stats: 6 lines in 2 files changed: 2 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/26966.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26966/head:pull/26966

PR: https://git.openjdk.org/jdk/pull/26966