RFR: CODETOOLS-7902980: jcstress: Scheduler fails on irregular architectures

[Aleksey Shipilev]

See bug report for details.

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Commit messages:
 - Improve tests
 - Make sure Scheduler can work with ragged topologies

Changes: https://git.openjdk.java.net/jcstress/pull/82/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jcstress&pr=82&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7902980
  Stats: 811 lines in 15 files changed: 426 ins; 372 del; 13 mod
  Patch: https://git.openjdk.java.net/jcstress/pull/82.diff
  Fetch: git fetch https://git.openjdk.java.net/jcstress pull/82/head:pull/82

PR: https://git.openjdk.java.net/jcstress/pull/82