“Goldman Sachs Group Inc. is buying General Motors Co. ’s credit-card business for about $2.5 billion, a deal that furthers the Wall Street giant’s push into Main Street lending. Goldman Sachs, a newcomer to the credit-card space, won the bidding over Barclays PLC, people familiar with the matter said, handing the Wall Street firm more than a million GM cardholders and their roughly $8.5 billion in annual spending.”