RFR: 8340008: KeyEvent/KeyTyped/Numpad1KeyTyped.java has 15 seconds timeout

[Alexey Ivanov]

I am open-sourcing the `Numpad1KeyTyped.java` test.

I used `CountDownLatch` for synchronisation.

The test passes in CI.

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Commit messages:
 - 8340008: KeyEvent/KeyTyped/Numpad1KeyTyped.java has 15 seconds timeout

Changes: https://git.openjdk.org/jdk/pull/21085/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21085&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340008
  Stats: 178 lines in 1 file changed: 178 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21085.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21085/head:pull/21085

PR: https://git.openjdk.org/jdk/pull/21085