Interactivity API: Ensure proper directive processing on special elem…

…ents.

Adds a test to ensure proper processing of directives on special HTML elements,
or HTML which contains special elements. These special elements are defined by
the HTML API and are the HTML elements which cannot contain other tags, such as
the IFRAME, SCRIPT, TEXTAREA, TITLE, elements, etc...

The server diretive processor performs a custom tracking of HTML structure and
this test ensures it isn't mislead by the handling of those special elements.

Developed in WordPress/wordpress-develop#6247
Discussed in https://core.trac.wordpress.org/ticket/60746

Props santosguillamot, cbravobernal, mukesh27, westonruter, swissspidy, dmsnell.
Follow-up to [57348].
Fixes #60746.


Built from https://develop.svn.wordpress.org/trunk@57822


git-svn-id: http://core.svn.wordpress.org/trunk@57323 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-alpha-57817';
+$wp_version = '6.6-alpha-57822';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.