Before 5.5, WordPress relied on hosting provider or user settings and plugins to handle purging or invalidating of core, plugin, and theme PHP changes. This resulted in problems for users like PHP fatal errors when a cached file included a file that had been deleted during an update.
As of [48160], WordPress attempts to invalidate PHP files when Core, Plugins, or Themes are updated.
To help with this, a new function is available, wp_opcache_invalidate(), a safe-to-call-directly wrapper for PHP’s native opcache_invalidate(). In order to avoid PHP warnings, the function handles the checks necessary to see whether OPcache is available, and
