Add safeguards for when ext/hash is not compiled with PHP.

see #29518, for trunk.

Built from https://develop.svn.wordpress.org/trunk@29751


git-svn-id: http://core.svn.wordpress.org/trunk@29523 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add some missing information to the inline docs for `get_post_types()`.

* Improves the `@see` reference for `register_post_type()` to mention that it contains information about accepted arguments
* Adds a description of the accepted values for the `$operator` parameter
* Fixes a typo

Fixes #29721.

Built from https://develop.svn.wordpress.org/trunk@29752


git-svn-id: http://core.svn.wordpress.org/trunk@29524 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add 'image_add_caption_text' filter for changing the pre-parse caption text before output to the editor.

props collinsinternet, DrewAPicture.
fixes #29607.
Built from https://develop.svn.wordpress.org/trunk@29753


git-svn-id: http://core.svn.wordpress.org/trunk@29525 1a063a9b-81f0-0310-95a4-ce76da25c4cd