If you're requesting help with building or using llvm-sys, please include
this information in addition to any other items (like compiler error messages)
that you think will be helpful:

 * version of llvm-sys you're using (either crate version or commit hash)
 * OS you're compiling on, including version if possible (example: Ubuntu 20.04
   or macOS 13)
 * what version of LLVM you're building against and where you got it from (from
   a package provided by your OS, built it yourself, using llvmenv..)
