RFR: 8274022 fixing critical memory leak in the ControlAcceleratorSupport

[Florian Kirmaier]

This fixes the new ControlAcceleratorBug which was Introduced in JavaFX17.
To fix it, I've made the Value of the WeakHashMap also weak. 
We only keep this value to remove it as a listener later on. Therefore there shouldn't be issues by making this value weak.


I've seen this Bug very very often, in the last weeks. Most of the applications I've seen are somehow affected by this bug.

It basically **breaks every application with menu bars and multiple stages** - which is the majority of enterprise applications. It's especially annoying because it takes some time until the application gets unstable.

Therefore **I would recommend** after this fix is approved, **to make a new version for JavaFX17** with this fix because this bug is so severe.

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Commit messages:
 - 8274022 fixing memory leak in the ControlAcceleratorSupport

Changes: https://git.openjdk.java.net/jfx/pull/659/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=659&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274022
  Stats: 39 lines in 2 files changed: 30 ins; 0 del; 9 mod
  Patch: https://git.openjdk.java.net/jfx/pull/659.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/659/head:pull/659

PR: https://git.openjdk.java.net/jfx/pull/659