对应文件夹下添加对应的三个库，获取Xcode9旧库（对你有帮助github给个star）
①在RuntimeRoot的lib里面增加libstdc++.6.0.9.dylib，libstdc++.6.dylib，libstdc++.dylib，路径如下：

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib（下文有进入目录方法）

②在iPhoneOS.sdk的lib里面增加libstdc++.6.0.9.tbd，libstdc++.6.tbd，libstdc++.tbd，路径如下：

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib/

③在iPhoneSimulator.sdk的lib里面增加libstdc++.6.0.9.tbd，libstdc++.6.tbd，libstdc++.tbd，路径如下：

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib/