Merge branch 'master' into 38869-datetime

* master: (85 commits)
  Export old code into es6 modules
  Use relative URL for projects to avoid storing domains
  Fix spec by avoiding monkeypatching
  Return the noteable in Note#touch_noteable
  add CHANGELOG.md entry for !15889
  fix broken empty state assets for environment monitoring page
  removed tab indexes from tag form
  Refactor entrypoint override docs
  Present member collection at the controller level
  Adds i18n
  check the import_status field before doing SQL operations to check the import url
  Fix rubocop offence
  Fix entrypoint overriding documentation
  Remove unnecessary js-issuable-edit
  Use memoization for commits on diffs
  Move Repository#write_ref to Git::Repository#write_ref
  Treat empty markdown and html strings as valid cached text, not missing cache that needs to be updated
  Center cluster title
  Remove noisy notification from QA base page
  Remove unused page from hashed storage QA scenario
  ...

app/assets/javascripts/merge_request_tabs.js

@@ -17,6 +17,7 @@ import Diff from './diff';
 import {
   localTimeAgo,
 } from './lib/utils/datetime_utility';
+import syntaxHighlight from './syntax_highlight';
 
 /* eslint-disable max-len */
 // MergeRequestTabs
@@ -298,7 +299,7 @@ import {
           }
 
           localTimeAgo($('.js-timeago', 'div#diffs'));
-          $('#diffs .js-syntax-highlight').syntaxHighlight();
+          syntaxHighlight($('#diffs .js-syntax-highlight'));
 
           if (this.diffViewType() === 'parallel' && this.isDiffAction(this.currentAction)) {
             this.expandViewContainer();