Addition of stdc++fs library

This is probably a moot point since this year is almost done and next year may include a newer GCC compiler with real C++17 support, but any plans to get the stdc++fs library compiled for G++ so that we can use the <experimental/filesystem> support on the roborio? This would be beneficial for us even after the season for post season projects.

This is a question for the WPILib team. Most of them are on here fairly often, but the best option is to ask in Github: https://github.com/wpilibsuite/allwpilib

Thanks I posted it there.