HHH-8680 Relax synchronized block in TableGenerator#generate

(cherry picked from commit adbd987fff7bb3a00a5b407741fd8a4270763f19)

Conflicts:

	hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java

hibernate-core/src/main/java/org/hibernate/id/enhanced/Optimizer.java

@@ -44,6 +44,9 @@ public interface Optimizer {
 	/**
 	 * Generate an identifier value accounting for this specific optimization.
 	 *
+	 * All known implementors are synchronized. Consider carefully if a new
+	 * implementation could drop this requirement.
+	 *
 	 * @param callback Callback to access the underlying value source.
 	 * @return The generated identifier value.
 	 */

hibernate-core/src/main/java/org/hibernate/id/enhanced/TableGenerator.java

@@ -463,7 +463,7 @@ public class TableGenerator implements PersistentIdentifierGenerator, Configurab
 	}
 
 	@Override
-	public synchronized Serializable generate(final SessionImplementor session, Object obj) {
+	public Serializable generate(final SessionImplementor session, final Object obj) {
 		final SqlStatementLogger statementLogger = session.getFactory().getServiceRegistry()
 				.getService( JdbcServices.class )
 				.getSqlStatementLogger();