[decorators] Correctly insert _initialize(this) after super(). (#8970)

* [decorators] Correctly insert `_initialize(this)` after `super()`.

This commit fixes to problem:
1) After `super();` statements, `_initialize(this)` was inserted without
   a trailing semicolon.
2) `(0, super())` causes an infinite recursion.

* Fix tests

* Add test

packages/babel-plugin-proposal-decorators/src/transformer.js

@@ -113,6 +113,10 @@ const bareSupersVisitor = {
   CallExpression(path, { initializeInstanceElements }) {
     if (path.get("callee").isSuper()) {
       path.insertAfter(t.cloneNode(initializeInstanceElements));
+
+      // Sometimes this path gets requeued (e.g. in (super(), foo)), and
+      // it leads to infinite recursion.
+      path.skip();
     }
   },
   Function(path) {