Change enum entry resolution strategy in JDR

Enum entry is now resolved into a class with a class object, which inherits
from the former class, as in the other parts of the compiler. Create a special
class EnumEntrySyntheticClassDescriptor which will be reused in deserialization
later

compiler/testData/loadJava/compiledJava/JavaEnum.java

@@ -1,6 +1,5 @@
 package test;
 
-//TODO: move to LoadJavaTestGenerated when possible
 public enum JavaEnum {
     ENTRY,
     ANOTHER;