This directory currently contains a strict subset of the output of cargo vendor.

The files were generated by running cargo vendor, and deleting all files we didn't want.

Specifically, this is https://github.com/dtolnay/cxx/blob/1.0.194/include/cxx.h

In the future, we will just vendor directly, but that adds ~60MB to the repo, so we will hold off on it for now.