升级了Mac系统和Xcode12版本后，运行iOS12、iOS13模拟器运行不起来，报如下错误：
Failed to start launchd_sim: could not bind to session, launchd_sim may have crashed or quit responding
Domain: com.apple.SimLaunchHostService.RequestError
Code: 4
解决方案一：
将 /usr/local/lib/libsafenet.dylib重命名，比如改成/usr/local/lib/libsafenet1.dylib后，系统就不会被这个安全库影响了，然后重启电脑后就能运行iOS12、iOS13系列模拟器了
解决方案二：
升级Mac系统，升级成最新的Mac OS Big Sur 11.0.1版本后就自动可以了 参考
When running on older iOS Simulator, error “Failed to start launchd_sim: could not bind to session, launchd_sim may have crashed or quit responding”
