Harry Guo built a life that defined success in China. Born in 1971, he came of age in the 1990s, when China deepened its economic reforms. He taught himself computing and found his way into jobs in multinational firms and then Chinese internet giants. By his mid-40s, he was comfortably middle class. He and his wife paid off two mortgages early and sent their daughter to high school and college in Canada. Then Mr. Guo was laid off. Now 55, he has not had a job in more than two…