horrible-harry/clang.md

Using clang

export CC=clang-6.0
export CXX=clang++-6.0
rm CMakeCache.txt
cmake .

Then make like "normal".

Where normal is getting things like:

Invalid opcode

?!? What the smeg ?!?

Also, apparently it takes different settings to tell clang to make a debug build. It doesn't with our config. Debugging invalid opcode was pretty much impossible.