JuliaLang/julia — pull request #4716 by loladiro (2013-11-02 23:19:12+00:00)
Title: Add flag to build LLVM with address sanitizer

Also adds the capability to download a custom copy of libcxx. Unfortunately I couldn't get this to work on OS X, even with a boostrapped clang, but I'll put this here in case it's useful for anyone (or myself later when I have more time).