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-modules-systemjs/test/fixtures/systemjs/hoist-function-exports/expected.js

@@ -2,6 +2,7 @@ System.register(["./evens"], function (_export, _context) {
   "use strict";
 
   var isEven, p, a, i, j, isOdd;
+
   function nextOdd(n) {
     return _export("p", p = isEven(n) ? n + 1 : n + 2);
   }
@@ -30,4 +31,4 @@ System.register(["./evens"], function (_export, _context) {
       _export("isOdd", isOdd);
     }
   };
-});
+});

packages/babel-plugin-transform-es2015-modules-systemjs/test/fixtures/systemjs/hoisting-bindings/expected.js

@@ -2,6 +2,7 @@ System.register([], function (_export, _context) {
   "use strict";
 
   var c;
+
   function a() {
     alert("a");
     _export("c", c + 1), c++;
@@ -23,4 +24,4 @@ System.register([], function (_export, _context) {
       b();
     }
   };
-});
+});

packages/babel-plugin-transform-es2015-modules-systemjs/test/fixtures/systemjs/remap/expected.js

@@ -10,6 +10,7 @@ System.register([], function (_export, _context) {
       _export("test", test);
 
       _export("test", test = 5);
+
       _export("test", test + 1), test++;
 
       (function () {