upgrades core to 8.4.2

core/misc/drupal.init.es6.js

@@ -0,0 +1,17 @@
+// Allow other JavaScript libraries to use $.
+if (window.jQuery) {
+  jQuery.noConflict();
+}
+
+// Class indicating that JS is enabled; used for styling purpose.
+document.documentElement.className += ' js';
+
+// JavaScript should be made compatible with libraries other than jQuery by
+// wrapping it in an anonymous closure.
+
+(function (domready, Drupal, drupalSettings) {
+  // Attach all behaviors.
+  domready(() => {
+    Drupal.attachBehaviors(document, drupalSettings);
+  });
+}(domready, Drupal, window.drupalSettings));