[arch-general] LLVM update blocker?

Hi, I'd like to ask if there's anything that is holding back upgrading the LLVM package to 3.8.0. (The package is already flaged out-of-date and I don't think this worth opening an issue for so I decided to ask here...) I'm aware that LLVM is famous for breaking API at every release and I know that clang is currently suffering from the GCC abi_tag issue so I can understand if some of these issues are holding back the upgrade. However, I would still like to know what is the issue (if any) since it would help me planing for the llvm-julia package and related stuff. Thanks, Yichao Yu