StackOverflowError in ObjectReferenceMapping

See attached stacktrace, it seems this happens if the init fails or something goes wrong creating the object graph. Version used: 2.7.7.v20200504-69f2c2b80d

```
java.lang.StackOverflowError
at org.eclipse.persistence.internal.descriptors.InstantiationPolicy.buildNewInstance(InstantiationPolicy.java:115)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildNewInstance(ObjectBuilder.java:670)
at org.eclipse.persistence.descriptors.copying.InstantiationCopyPolicy.buildClone(InstantiationCopyPolicy.java:33)
at org.eclipse.persistence.descriptors.copying.AbstractCopyPolicy.buildWorkingCopyClone(AbstractCopyPolicy.java:45)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.instantiateWorkingCopyClone(ObjectBuilder.java:4026)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1058)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1006)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:4066)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:3995)
at org.eclipse.persistence.mappings.ObjectReferenceMapping.buildUnitofWorkCloneForPartObject(ObjectReferenceMapping.java:136)
at org.eclipse.persistence.mappings.ObjectReferenceMapping.buildCloneForPartObject(ObjectReferenceMapping.java:98)
at org.eclipse.persistence.internal.indirection.NoIndirectionPolicy.cloneAttribute(NoIndirectionPolicy.java:81)
at org.eclipse.persistence.mappings.ForeignReferenceMapping.buildClone(ForeignReferenceMapping.java:316)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.populateAttributesForClone(ObjectBuilder.java:4181)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.populateAndRegisterObject(UnitOfWorkImpl.java:3774)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1077)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1006)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:4066)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:3995)
at org.eclipse.persistence.mappings.ObjectReferenceMapping.buildUnitofWorkCloneForPartObject(ObjectReferenceMapping.java:136)
at org.eclipse.persistence.mappings.ObjectReferenceMapping.buildCloneForPartObject(ObjectReferenceMapping.java:98)
at org.eclipse.persistence.internal.indirection.NoIndirectionPolicy.cloneAttribute(NoIndirectionPolicy.java:81)
at org.eclipse.persistence.mappings.ForeignReferenceMapping.buildClone(ForeignReferenceMapping.java:316)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.populateAttributesForClone(ObjectBuilder.java:4181)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.populateAndRegisterObject(UnitOfWorkImpl.java:3774)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1077)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:1006)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:4066)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:3995)
at org.eclipse.persistence.mappings.ObjectReferenceMapping.buildUnitofWorkCloneForPartObject(ObjectReferenceMapping.java:136)
```

Reproduce the failure with EclipseLink 2.7.7.v20200504-69f2c2b80d using the object-graph setup that fails during initialization. Start at ObjectReferenceMapping.java and trace the repeated cloneAndRegisterObject/registerExistingObject calls in the stack trace; done means the failing scenario no longer overflows the stack.

Written by the indexing model from the issue text.