Shares of chip-design software maker Synopsys plummeted in extended trading after warning that US export restrictions are contributing to a slowdown in China, the largest market for semiconductors.As part of the company’s quarterly report on Tuesday, CEO Sassine Ghazi said that a push to develop its own intellectual property (IP) was not achieving the desired results – partly because of the challenges in China.Ghazi said he would be refocusing resources on other areas and was reducing the...