Following [56635], a fatal error occurred in `load-styles.php` leading to admin styles not working, because of a `has_filter()` call being added to `get_stylesheet_director()` and `get_template_directory()`.
This changeset adds `has_filter()` to `wp-admin/includes/noop.php` to prevent such errors. The lack of loading the function does not cause any unintended side effects itself.
Props iandunn, adamsilverstein.
Fixes#59417.
See #18298.
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git-svn-id: http://core.svn.wordpress.org/trunk@56153 1a063a9b-81f0-0310-95a4-ce76da25c4cd