Remove whitespace generation (#5833)

* 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

packages/babel-plugin-transform-react-inline-elements/test/fixtures/inline-elements/ref-deopt/expected.js

@@ -1 +1,3 @@
-React.createElement(Foo, { ref: "bar" });
+React.createElement(Foo, {
+  ref: "bar"
+});