JEP update: Classes for the Basic Primitives

[Dan Smith]

I'm made some revisions to JEP 402 to better track with the revised JEP 401—in particular backing off of "everything is an object".

There were some short-lived changes where I more aggressively pursued the idea that the class was named 'int', but I've backed off of that, too. Now taking the more conservative approach that there is a primitive class named 'Integer', but by special rule its primitive type is expressed 'int', and the class name refers to the reference type.

I realize that much of this could potentially change—reflection story, terminology, etc. But consider this the "plan of record" for now.

https://bugs.openjdk.java.net/browse/JDK-8259731