[valhalla/jep390] Diagnose synchronization on @ValueBased classes

Enhance the work done in JDK-8242263 to warn about synchronization performed on any class that is declared with a @ValueBased annotation.

The same behaviors as implemented by JDK-8242263 should apply—VM abort, logged warning, or JFR event.

The -XX:DiagnoseSyncOnPrimitiveWrappers flag should probably be renamed to indicate that it's a check on all value-based classes. (It is probably *not* useful to have two different knobs, one for primitives and one for other value-based classes.)