#133 Move constant class TypeDetails from interface to dedicated class

[mbellade]

Fixes #133.

Moving static constant ClassTypeDetailsImpl references to a dedicated class to avoid deadlocks waiting on <clinit> of the ClassBasedTypeDetails interface.

[sebersole]

Looks good.

However, have you seen actual cases of this being a problem? The reason I ask is that we'd need a release of models and update orm to use it. But that new release would also include the work for #128, of which I am a little nervous about the performance impact.

[mbellade]

Yeah, I've tried the reproducer provided here by Andres, which is fairly straightforward, and it confirmed the application got deadlocked waiting for ClassBasedTypeDetails. I've then tried applying these changes and the code execution finished in just a few moments.

The original report https://issues.redhat.com/browse/WFLY-20615 also says this can occur when using Wildfly and having 2 JPA applications deploying at the same time.

[sebersole]

Ok, then we'll just have to hope #128 does not introduce a performance problem - all for a feature we are not even using in ORM yet ;)