Discriminate between the lldb_private::Type's for ObjC Classes that come from...

Discriminate between the lldb_private::Type's for ObjC Classes that come from debug info, and those that
are made up from the ObjC runtime symbols.  For now the latter contain nothing but the fact that the name
describes an ObjC class, and so are not useful for things like dynamic types.

llvm-svn: 148059