Generated set should include its root types
Generated set should include its root types

Summary:
When compute the generated type set, we should also include the other roots given in the config.
This is useful when the generated code is a single class without a inheritance hierarchy.

Reviewed By: shanenay

Differential Revision: D10468998

fbshipit-source-id: edaf0abdeaf4565e8068db117ce4f5e1b68a24aa

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex