文件转载自互联网，好像是github…
1.下载资源文件
https://download.csdn.net/download/cl61917380/10799829
2.将其中文件夹 1、2、3、4 中的文件分别对应复制到Xcode10中的以下4个目录中即可：
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib/
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib/
3.对应的shell为
sudo cp /Users/su/Downloads/download_git/libstdc/1/libstdc++.* /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/
sudo cp /Users/su/Downloads/download_git/libstdc/2/libstdc++.* /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/
sudo cp /Users/su/Downloads/download_git/libstdc/3/libstdc++.* /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib/
sudo cp /Users/su/Downloads/download_git/libstdc/4/libstdc++.* /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib/
其中
/Users/su/Downloads/download_git/libstdc/
为我的文件目录