[jfx22] RFR: 8322215: [win] OS events that close the stage can cause Glass to reference freed memory

[Martin Fox]

This pull request contains a backport of commit [c1c52e5a](https://github.com/openjdk/jfx/commit/c1c52e5a42f9a4319487aa9db8e8fcbcf1ba02c8) from the [openjdk/jfx](https://git.openjdk.org/jfx) repository.

The commit being backported was authored by Martin Fox on 22 Jan 2024 and was reviewed by Michael Strauß and Kevin Rushforth.

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Commit messages:
 - Backport c1c52e5a42f9a4319487aa9db8e8fcbcf1ba02c8

Changes: https://git.openjdk.org/jfx/pull/1347/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1347&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8322215
  Stats: 32 lines in 2 files changed: 30 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jfx/pull/1347.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1347/head:pull/1347

PR: https://git.openjdk.org/jfx/pull/1347