RFR: 8359601: Fix window button states of an extended stage [v3]

[Michael Strauß]

On Sat, 21 Jun 2025 17:37:02 GMT, Markus Mack <mmack at openjdk.org> wrote:

> I also checked the behavior in macOS Sequoia 15.5. There, a window where `setResizable(false)` is called before showing the stage, unexpectedly has a working maximize button even without `StageStyle.EXTENDED`. Looks like this was not the case prior to the integration of #1605, so this behavior was probably introduced there and may need a fix in this PR or elsewhere.

The implementation relied on the `_setResizable` JNI method being called in a very particular way that has since changed (internally, it would call another method with the same name, but the implementation would actually _toggle_ the resizable state, not _set_ it to a given value). I've fixed this problem.

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PR Comment: https://git.openjdk.org/jfx/pull/1831#issuecomment-2993820442