RFR: CODETOOLS-7902827: JCStress: Start testing with JDK 17 EA

[Aleksey Shipilev]

JDK mainline had switched development to JDK 17 EA, we should be adding that version to pipelines.

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Commit messages:
 - CODETOOLS-7902827: JCStress: Start testing with JDK 17 EA

Changes: https://git.openjdk.java.net/jcstress/pull/6/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jcstress&pr=6&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7902827
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jcstress/pull/6.diff
  Fetch: git fetch https://git.openjdk.java.net/jcstress pull/6/head:pull/6

PR: https://git.openjdk.java.net/jcstress/pull/6