| It is often convenient to be able to build compiler-rt libraries for a certain | |
| platform without having a full SDK or development environment installed. | |
| This makes it easy for users to build a compiler which can target a number of | |
| different platforms, without having to actively maintain full development | |
| environments for those platforms. | |
| Since compiler-rt's libraries typically have minimal interaction with the | |
| system, we achieve this by stubbing out the SDKs of certain platforms. |