* Remove whitespace generation and rely on default printing
Changes to printing:
* Add newline after last empty SwitchCase
* Add newlines around block comments if they are non-flow comments or contain newlines
* Fix a few more fixtures
When convert a const, let or any other block-bound binding to a var we
forget to update the scope info. This confuses other transforms that may
come after this as to which scope does the binding belongs to.
This also uncovered an issue where duplicate block-scoped bindings were allowed
to co-exist.
