Synopsys offices in Mountain View, California.Photographer: David Paul Morris/BloombergShares of chip-design software maker Synopsys Inc. 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 reportBloomberg Terminal on Tuesday, Chief Executive Officer Sassine Ghazi said that a push to develop its own intellectual property isn’t achieving the desired results — partl...