Repository is outdated

[JayFoxRox]

@jyasskin and @google: This repository appears to have been abandoned since 2012.
I hope this isn't used in production anymore, in case there were security bugs in libcxx.

By now, the upstream project has moved to GitHub (as a subfolder) in https://github.com/llvm/llvm-project/tree/master/libcxx

I suggest that this repository is deleted. If the branches are stil required, I'd suggest to refork the llvm repository, and rebase the additions.

[jyasskin]

Indeed. I've pinged the folks who can delete it.