RFR: 8305666: Add system property for fair AWT lock

Wed Apr 5 16:02:21 UTC 2023

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.

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Commit messages:
 - 8305666: Add system property for fair AWT lock

Changes: https://git.openjdk.org/jdk/pull/13356/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13356&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305666
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/13356.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13356/head:pull/13356

PR: https://git.openjdk.org/jdk/pull/13356