Constraint generator incorrectly generates reference type constraints in some circumstances

[JohnTimm]

A bug was introduced from this commit:

28f4628

This will cause profile-generated reference type constraints with multiple targets to fail validation for non-repeating elements. For example:

value.as(Reference).exists() implies (value.as(Reference).resolve().is(Practitioner) or resolve().is(PractitionerRole) or resolve().is(Organization) or resolve().is(Location))

should be:

value.as(Reference).exists() implies (value.as(Reference).resolve().is(Practitioner) or value.as(Reference).resolve().is(PractitionerRole) or value.as(Reference).resolve().is(Organization) or value.as(Reference).resolve().is(Location))