Javadoc
Create and return an AccessEnabler to manage enabling
reflective access.
For JDK8 and lower releases return a DefaultAccessEnabler
which does not now about module encapsulation.
For JDK9 and higher releases return a JigsawAccessEnabler
which is capable of enabling access to members of classes which
are normally inaccessible because of module restrictions.
caveat: during testing class JigsawAccessEnabler may fail to
load even thought the JDK is modular. That happens when testing
that the JDK8- core classes work without the JDK9 code present.
In this specific situation a DefaultAccessEnabler is returned.
A helper trace message is logged just in case.