Update LLVM/Clang to v4.0.0

[ivanbuhov]

To update to llvm 3.8:

1. Download the pre-build binary of LLVM 4.0.0 with Clang for Mac OS X.
2. Extract the content of the package (/usr/local/lib is a good candidate for a destination folder)
3. Include the path to {llvm-root}/bin/llvm-config or symlink to it in your PATH
4. Reset the cmake cache of the metadata generator project. This way the generator will be linked with the new version of Clang/LLVM.

[mm-ns]

Hi Ivan, I am the person that reported this to Sebastian, so I appreciate your support on this. What would you say the time estimate on this is?

[ivanbuhov]

@mm-ns Correct me if I am wrong but aren't you talking about this issue. If no - can you give more details on your issue related to the LLVM/Clang update in the iOS runtime. If yes - let's continue the discussion there.

Assuming that your comment is actually related to this one: we are going to further investigate the issue and update its status once {N} 3.2 is live.