Revert dist changes from #32747 (#33050)

js/dist/popover.js

@@ -52,7 +52,17 @@
   function _inheritsLoose(subClass, superClass) {
     subClass.prototype = Object.create(superClass.prototype);
     subClass.prototype.constructor = subClass;
-    subClass.__proto__ = superClass;
+
+    _setPrototypeOf(subClass, superClass);
+  }
+
+  function _setPrototypeOf(o, p) {
+    _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
+      o.__proto__ = p;
+      return o;
+    };
+
+    return _setPrototypeOf(o, p);
   }
 
   /**
@@ -226,8 +236,8 @@
 
     _createClass(Popover, null, [{
       key: "Default",
-      // Getters
-      get: function get() {
+      get: // Getters
+      function get() {
         return Default;
       }
     }, {