reverted:
--- b/core-js-offset-mess-1870006-10.patch
+++ /dev/null
@@ -1,84 +0,0 @@
-diff --git a/core/misc/offset/fragment.js b/core/misc/offset/fragment.js
-new file mode 100644
-index 0000000..b2aac4f
---- /dev/null
-+++ b/core/misc/offset/fragment.js
-@@ -0,0 +1,26 @@
-+/**
-+ * @file
-+ * Offsets the window to allow fragments navigation with fixed positioning elements.
-+ */
-+(function ($, Drupal, displace) {
-+
-+  "use strict";
-+
-+  function adjustOffset () {
-+    var hash = window.location.hash;
-+    if (hash) {
-+      var element = document.getElementById(hash.replace('#', ''));
-+      if (element) {
-+        // Display the element in the viewport.
-+        setTimeout(function () {
-+          window.scrollTo(0, $(element).offset().top - displace.offsets.top);
-+        }, 5);
-+      }
-+    }
-+  }
-+
-+  // Checks for a fragment on page load, outside Drupal behaviors.
-+  Drupal.behaviors.adjustOffset = { attach: adjustOffset };
-+  $(window).on('hashchange', adjustOffset);
-+
-+})(jQuery, Drupal, Drupal.displace);
-diff --git a/core/misc/offset/html5forms.js b/core/misc/offset/html5forms.js
-new file mode 100644
-index 0000000..32e0d33
---- /dev/null
-+++ b/core/misc/offset/html5forms.js
-@@ -0,0 +1,13 @@
-+/**
-+ * @file
-+ * Focus the HTML5 validation error in view.
-+ */
-+(function (displace) {
-+
-+  "use strict";
-+
-+  document.addEventListener('invalid', function (event) {
-+    setTimeout(function () { window.scrollBy(0, -displace.offsets.top); }, 5);
-+  }, true);
-+
-+})(Drupal.displace);
-diff --git a/core/modules/system/system.module b/core/modules/system/system.module
-index 10bc48d..364e848 100644
---- a/core/modules/system/system.module
-+++ b/core/modules/system/system.module
-@@ -952,6 +952,10 @@ function system_library_info() {
-     'version' => Drupal::VERSION,
-     'js' => array(
-       'core/misc/drupal.js' => array('group' => JS_LIBRARY, 'weight' => -18),
-+      'core/misc/debounce.js' => array('group' => JS_LIBRARY),
-+      'core/misc/displace.js' => array('group' => JS_LIBRARY),
-+      'core/misc/offset/fragment.js' => array('group' => JS_LIBRARY),
-+      'core/misc/offset/html5forms.js' => array('group' => JS_LIBRARY),
-     ),
-     'dependencies' => array(
-       array('system', 'domready'),
-@@ -1162,7 +1166,7 @@ function system_library_info() {
-     'title' => 'Drupal displace',
-     'version' => Drupal::VERSION,
-     'js' => array(
--      'core/misc/displace.js' => array('group' => JS_LIBRARY),
-+      //'core/misc/displace.js' => array('group' => JS_LIBRARY),
-     ),
-     'dependencies' => array(
-       array('system', 'jquery'),
-@@ -1191,7 +1195,7 @@ function system_library_info() {
-     'title' => 'Drupal debounce',
-     'version' => Drupal::VERSION,
-     'js' => array(
--      'core/misc/debounce.js' => array('group' => JS_LIBRARY),
-+      //'core/misc/debounce.js' => array('group' => JS_LIBRARY),
-     ),
-     'dependencies' => array(
-       // @todo remove drupal dependency.
diff -u b/core/misc/offset/fragment.js b/core/misc/offset/fragment.js
--- b/core/misc/offset/fragment.js
+++ b/core/misc/offset/fragment.js
@@ -1,17 +1,19 @@
 /**
- * @file
- * Offsets the window to allow fragments navigation with fixed positioning elements.
- */
+* DO NOT EDIT THIS FILE.
+* See the following change record for more information,
+* https://www.drupal.org/node/2815083
+* @preserve
+**/
+
 (function ($, Drupal, displace) {
 
   "use strict";
 
-  function adjustOffset () {
+  function adjustOffset() {
     var hash = window.location.hash;
     if (hash) {
       var element = document.getElementById(hash.replace('#', ''));
       if (element) {
-        // Display the element in the viewport.
         setTimeout(function () {
           window.scrollTo(0, $(element).offset().top - displace.offsets.top);
         }, 5);
@@ -21,6 +23,4 @@
 
-  // Checks for a fragment on page load, outside Drupal behaviors.
   Drupal.behaviors.adjustOffset = { attach: adjustOffset };
   $(window).on('hashchange', adjustOffset);
-
 })(jQuery, Drupal, Drupal.displace);
\ No newline at end of file
diff -u b/core/misc/offset/html5forms.js b/core/misc/offset/html5forms.js
--- b/core/misc/offset/html5forms.js
+++ b/core/misc/offset/html5forms.js
@@ -1,13 +1,17 @@
 /**
- * @file
- * Focus the HTML5 validation error in view.
- */
+* DO NOT EDIT THIS FILE.
+* See the following change record for more information,
+* https://www.drupal.org/node/2815083
+* @preserve
+**/
+
 (function (displace) {
 
   "use strict";
 
   document.addEventListener('invalid', function (event) {
-    setTimeout(function () { window.scrollBy(0, -displace.offsets.top); }, 5);
+    setTimeout(function () {
+      window.scrollBy(0, -displace.offsets.top);
+    }, 5);
   }, true);
-
 })(Drupal.displace);
\ No newline at end of file
only in patch2:
unchanged:
--- a/core/core.libraries.yml
+++ b/core/core.libraries.yml
@@ -215,10 +215,13 @@ drupal.form:
   version: VERSION
   js:
     misc/form.js: {}
+    misc/offset/fragment.js: {}
+    misc/offset/html5forms.js: {}
   dependencies:
     - core/jquery
     - core/drupal
     - core/drupal.debounce
+    - core/drupal.displace
     - core/jquery.cookie
     - core/jquery.once
 
only in patch2:
unchanged:
--- /dev/null
+++ b/core/misc/offset/fragment.es6.js
@@ -0,0 +1,26 @@
+/**
+ * @file
+ * Offsets the window to allow fragments navigation with fixed positioning elements.
+ */
+(function ($, Drupal, displace) {
+
+  "use strict";
+
+  function adjustOffset () {
+    var hash = window.location.hash;
+    if (hash) {
+      var element = document.getElementById(hash.replace('#', ''));
+      if (element) {
+        // Display the element in the viewport.
+        setTimeout(function () {
+          window.scrollTo(0, $(element).offset().top - displace.offsets.top);
+        }, 5);
+      }
+    }
+  }
+
+  // Checks for a fragment on page load, outside Drupal behaviors.
+  Drupal.behaviors.adjustOffset = { attach: adjustOffset };
+  $(window).on('hashchange', adjustOffset);
+
+})(jQuery, Drupal, Drupal.displace);
only in patch2:
unchanged:
--- /dev/null
+++ b/core/misc/offset/html5forms.es6.js
@@ -0,0 +1,13 @@
+/**
+ * @file
+ * Focus the HTML5 validation error in view.
+ */
+(function (displace) {
+
+  "use strict";
+
+  document.addEventListener('invalid', function (event) {
+    setTimeout(function () { window.scrollBy(0, -displace.offsets.top); }, 5);
+  }, true);
+
+})(Drupal.displace);