[jdk25u] RFR: 8333526: Restructure java/nio/channels/DatagramChannel/StressNativeSignal.java to a fail fast exception handling policy

[Anawesha Khuntia]

Had run the tier1 - tier3 tests and there were no valid failures due to the fix

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Commit messages:
 - Backport 4f4030a423d04c8f488d143f0eda4a8de9dbd469

Changes: https://git.openjdk.org/jdk25u/pull/296/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=296&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333526
  Stats: 57 lines in 1 file changed: 0 ins; 27 del; 30 mod
  Patch: https://git.openjdk.org/jdk25u/pull/296.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/296/head:pull/296

PR: https://git.openjdk.org/jdk25u/pull/296