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-es2015-function-name/test/fixtures/function-name/object/expected.js

@@ -4,7 +4,6 @@ var obj = {
       console.log(f);
     })();
   },
-
   h: function (_h) {
     function h() {
       return _h.apply(this, arguments);
@@ -18,8 +17,7 @@ var obj = {
   }(function () {
     console.log(h);
   }),
-
   m: function m() {
     doSmth();
   }
-};
+};