Prints the compiler arguments needed to run Clang against the kernel headers. We use this for running libclang from bindgen.

Normal usage: run make -s and look at stdout (errors go to stderr). If you need to build for a specific set of kernel headers, add something like KDIR=/lib/modules/3.16.0-4-amd64/build. If your clang command is not clang, add something like CLANG=clang-3.8.

This generates a non-functional kernel module in the process. To clean up, make clean.