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/export/expected.js

@@ -2,8 +2,8 @@ export { _whatever as whatever };
 export { _wowzers as default };
 var _foo = "yes",
     foob = "no";
-
 export { _foo as foo, foob };
+
 function _whatever() {}
 
 function _wowzers() {}
@@ -12,12 +12,10 @@ var bar = {
   foo: function foo() {
     _foo;
   },
-
   whatever: function whatever() {
     _whatever;
   },
-
   wowzers: function wowzers() {
     _wowzers;
   }
-};
+};