Missing dummy parents: TypeCreator and Trees$Transformer

[sjrd]

These show up as parent classes of some synthetic classes generated by macros, for macros. They're not really necessary at runtime (AFAICT), but under packageJS the initialization code blows up because they are used as parent classes.

[sjrd]

See also: https://groups.google.com/forum/#!topic/scala-js/c2OdPimYsdQ