Complete java.lang.Class items

[dmlloyd]

More things to consider:

• Migrate getArrayClass() to pure Java
• Use type_id type for nestHost, etc. (use patcher to delete the "originals" of these fields) (nestMembers should remain an object array though)
• Drop (patch away) other fields from Class that we don't need, such as componentType, classRedefinedCount
• Pre-initialize enumConstants
• Implement isInstance, isAssignableFrom in pure Java
• Migrate other fields like modifiers
• Accept classData argument in "normal" ctor for definition of "hidden" classes
• Do the same for java.lang.Object, including specifying the type ID field in Java and implementing getClass() in terms of the type ID value

Originally posted by @dmlloyd in #108 (comment)