To fiddle around with what it does, run `composer install` from the project root. If you do not have Composer installed:
https://getcomposer.org/doc/00-intro.md#locally
tl;dr for Mac/Homebrew users: `brew install composer`
Classes from `wp-includes` and `wp-admin` are eligible for autoloading via `autoload.classmap`. Through a tornado of recent commits, many unsuitable files have been transitioned into a more acceptable state for autoloading: 1 file per class, no side effects.
The file bootstrap in `wp-settings.php` can transition into `autoload.files`. This will be done with care and attention.
See #36335.
git-svn-id: https://develop.svn.wordpress.org/trunk@38384 602fd350-edb4-49c9-b593-d223f7449a82
