DETROIT — A federal bankruptcy judge has ruled that people suing General Motors over faulty ignition switches can seek punitive damages that could cost the company millions of dollars or more.When General Motors emerged from a 2009 bankruptcy, it became known as “New GM.” The new company essentially was shielded from liabilities of the old company that was left behind.But Judge Robert Gerber in New York ruled Monday that employees and knowledge transferred from the “Old GM” to the new company. …