[$] Building the kernel with clang

Over the years, there has been a persistent effort to build the Linuxkernel using the Clang C compiler that is part of the LLVM project. Welast looked in on the effort in a report fromthe LLVM microconference at the 2015 Linux Plumbers Conference (LPC), but wehave followed it before that aswell. At this year's LPC, two Google kernel engineers, Greg Hackmann andNick Desaulniers, came to the Androidmicroconference to update the status; at this point, it is possible tobuild two long-term support kernels (4.4 and 4.9) with Clang.