RFR: 8305666: Add system property for fair AWT lock

[Phil Race]

On Wed, 5 Apr 2023 15:54:53 GMT, Nikita Gubarkov <ngubarkov at openjdk.org> wrote:

> There are freezes reported on some Linux configurations which are believed to may be caused by the toolkit thread quickly reacquiring AWT_LOCK while polling for events, which starves EDT waiting on that lock.
> Adding new `awt.lock.fair` system property can help diagnosing such issues.

fair :-) enough/

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Marked as reviewed by prr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13356#pullrequestreview-1375849655