RFR: 8351345: Test: Print out non-whitelisted JTreg VM or Javaoptions flag

[Hamlin Li]

Hi,
Can you help to review this trivial patch?
Currently, it only reports that some flag is non-whitelisted, but does not print out the flag explicitly, but it's helpful to do so.

Thanks!

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/23931/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23931&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351345
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23931.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23931/head:pull/23931

PR: https://git.openjdk.org/jdk/pull/23931