For building with llvm toolchain (tested with 3.4.2, 3.8, 3.9)
make ARCH=x86_64 CC=clang defconfig
make ARCH=x86_64 CC=clang
Optionally:
HOSTCC=clang KBUILD_OUTPUT=build-dir
Now allyesconfig is fine, except KASAN.
Make sure enable CONFIG_X86_INTEL_MPX in the .config file. To enable the MPX ISs.