RFR: 8252182: [JEP 390] Diagnose synchronization on @ValueBased classes [v2]

[Lois Foltan]

> Please review the following changes to add JVM support for @ValueBased class annotation.

Lois Foltan has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:

 - Merge branch 'jep390' into bug_8252182
 - 8252182: [JEP 390] Diagnose synchronization on @ValueBased classes
 - 8252182: [JEP 390] Diagnose synchronization on @ValueBased classes

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Changes: https://git.openjdk.java.net/valhalla/pull/274/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=274&range=01
  Stats: 314 lines in 34 files changed: 135 ins; 101 del; 78 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/274.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/274/head:pull/274

PR: https://git.openjdk.java.net/valhalla/pull/274