Hallo Gerrit!

 GK> FreeBSD completely switched already some time ago

According to https://en.wikipedia.org/wiki/Clang;

  25 February 2009  Clang/LLVM can compile a working FreeBSD kernel.
  10 June 2010      Clang/LLVM becomes integral part of FreeBSD, but
default compiler is still GCC.
  12 May 2012       Clang/LLVM announced to replace GCC in FreeBSD.
  5 November 2012   Clang becomes default compiler in FreeBSD 10.x.

I don't see any claims for a Linux kernel, nor as a default compiler on any
Linux distribution.  They do mention something about Debian which, given
the eglibc support of days gone by, isn't really a feather in clang's cap
... if you know what I mean.

Anyhow I have built llvm with clang in the past and I suspect it is still
doable but I have serious doubts about it compiling standard Linux source
from kernel.org without some major hacking/patching.  Also I haven't
installed clang on anything here yet and it'll be awhile since I am just
upgrading the raspberrypi as we speak.  I guesstimate some clang
kernel/glibc action sometime early next week.  For me those are the two
most mission critical packages and will tell the tale.

Het leven is goed,
Maurice

... Huil niet om mij, ik heb vi.
--- GNU bash, version 5.0.11(1)-release (x86_64-silvermont-linux-gnu)