Last modified: 2012-11-23 18:10:41 UTC
From https://www.mediawiki.org/wiki/CheckSyntax.php --modified check only files modified in the current working copy (requires that the script is run from a Subversion checkout and that the SVN command-line client is present. Use this option to quickly check your changes before committing them to the repository. This should be updated for git support.
Looks like this is in core, not code-utils.
This was done in Gerrit change #4387. Just need to update the wiki page.