compile with llvm head

I don't have a very good understanding of `llvm` internals, but to the best of my knowledge these commits are what is required to build with `llvm` head.

With these, the project builds with revision 183111:

    areece-macbook-pro:creduce areece$ llvm-config --version
    3.4svn
    areece-macbook-pro:creduce areece$ clang --version
    clang version 3.4 
    Target: x86_64-apple-darwin12.3.0
    Thread model: posix

I ran the tests as well, but I actually don't know how to interpret the results. I think they almost all passed? Here is some info, and I'll send more if you tell me what to look for. https://gist.github.com/awreece/5703282