wp-admin/includes/upgrade.php:2176Executes changes made in WordPress 5.0.0.
function upgrade_500() {}Introduced in 5.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/upgrade.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.