HHH-8923 - Reconsider closing of ServiceRegistry instances

Conflicts:
	hibernate-core/src/main/java/org/hibernate/boot/registry/internal/BootstrapServiceRegistryImpl.java
	hibernate-core/src/main/java/org/hibernate/boot/registry/internal/StandardServiceRegistryImpl.java
	hibernate-core/src/main/java/org/hibernate/service/internal/AbstractServiceRegistryImpl.java
	hibernate-testing/src/main/java/org/hibernate/testing/junit4/BaseCoreFunctionalTestCase.java
HHH-8923 corrected test case