RFR: CODETOOLS-7903052: jcstress: Failure witness examples

[Aleksey Shipilev]

We need to improve the jcstress samples with some failure witness examples.

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Commit messages:
 - Failure witness examples

Changes: https://git.openjdk.java.net/jcstress/pull/96/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jcstress&pr=96&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7903052
  Stats: 419 lines in 3 files changed: 419 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jcstress/pull/96.diff
  Fetch: git fetch https://git.openjdk.java.net/jcstress pull/96/head:pull/96

PR: https://git.openjdk.java.net/jcstress/pull/96