Real classes that begin with '_' will have a Package name

A large project that I support uses a modified version of Underscore.as. This works fine when referencing the source but once it is compiled into a swc those classes become invisible to the autocomplete. 

After testing on a project with a large amount of swc references, the difference between a compiler generated class that starts with '_' and a real class is that the generated class does not have a package name.