Thnks for watch my question,
LLVM does not define it's own C++ standard. You are asking for the
coding style, I guess? Or you're really asking about the C++ standard?
You have to pay for current C++ standard if I remember correctly. Or
you can find the working draft copy which is close to the standard one.
This kind of question is more related to clang (a compiler frontend
for LLVM). Clang has it's own ML.