Broadcom Inc. shares jumped after OpenAI agreed to buy the company’s custom chips and networking equipment in a multiyear deal, part of an ambitious plan by the startup to add artificial intelligence infrastructure.As part of the pact, OpenAI will design the hardware and work with Broadcom to develop it, according to a joint statement on Monday. The plan is to add 10 gigawatts’ worth of AI data center capacity, with the companies beginning to deploy racks of servers containing the gear in the second half of ...