Message Title

I don't seem to have rights to update the issue, but I can verify that this still fails in 5.0. I have run the test from this PR on the master pointing to commit e6c1f511a30816963901fb4746163a849dd80226.
javax.persistence.PersistenceException: [PersistenceUnit: MappingClassMoreThanOnceTest] Unable to build Hibernate SessionFactory
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:877)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:805)
	at org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase.buildEntityManagerFactory(BaseEntityManagerFunctionalTestCase.java:78)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.junit.internal.runners.statements.FailOnTimeout$StatementThread.run(FailOnTimeout.java:74)
Caused by: javax.persistence.PersistenceException: Error build callback listeners; entity [org.hibernate.jpa.test.multimappingperclass.Entity was already processed
	at org.hibernate.jpa.event.internal.jpa.CallbackRegistryImpl.addEntityCallbacks(CallbackRegistryImpl.java:114)
	at org.hibernate.jpa.event.internal.jpa.LegacyCallbackProcessor.processCallbacksForEntity(LegacyCallbackProcessor.java:55)
	at org.hibernate.jpa.event.spi.JpaIntegrator.integrate(JpaIntegrator.java:140)
	at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:278)
	at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:802)
	... 11 more