[jdk25u] RFR: 8346884: Add since checker test to jdk.editpad

[Hari Prasad Kummari]

Tested local changes and no failure found.

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Commit messages:
 - backport 7daf9813c0617ea97d95bf326eac1758e40cddd6

Changes: https://git.openjdk.org/jdk25u/pull/333/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=333&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346884
  Stats: 30 lines in 1 file changed: 30 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk25u/pull/333.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/333/head:pull/333

PR: https://git.openjdk.org/jdk25u/pull/333