The effort of building the Linux kernel with Clang as an alternative to GCC has been pushed under the LLVMLinux initiative, which is hosted by the Linux Foundation. However, over the past number of months it has been very quiet and we haven't been seeing many Clang-related patches in recent Linux kernel cycles.
Given how quiet it's been, not seeing many new patches, and the LLVMLinux site not seeing much in the way of updates since 2014, I reached out to Behan Webster. Behan has presented at Linux conferences several times on the prospects of compiling the Linux kernel with Clang, the patches they carry in their tree to achieve this feat, etc. He explained the situation in an email to me as:
Theoretically yes [being involved with the project]. The issue is that most of the people involved got busy with other things in 2015. I'm hoping we can find more time in 2016.It would be lovely to see the mainline LLVM Clang compiler able to compile the mainline Linux kernel for x86_64 and ARM, let's hope that this will be the year when it can finally happen!
Honestly he just got a lot less press in 2014, and simultaneously the project lost steam. A bunch of our day jobs changed at the end of 2014 which is the major reason.