The /third_party directory is for any code that doesn't follow Carbon's normal
contribution rules, and thus requires special care. The intent is that code
not under /third_party should not require special contribution rules.
Examples of code belonging under /third_party include:
- Code not licensed under the standard Apache-2.0 WITH LLVM-exception license.
- Code which is maintained externally or imported from another repository.
- Code which is not fully under Carbon's CLA.