message: Remove ARCH_K8 from x86_64 toolchain configurations.
  Nothing in Tensorflow depends on it being defined.
diff: @@ -531,7 +531,6 @@ toolchain {
  linker_flag: "-L/usr/lib/gcc/x86_64-linux-gnu/4.8"
  # This is the minimum x86 architecture TensorFlow supports.
  - compiler_flag: "-DARCH_K8"
  compiler_flag: "-m64"
  # These are for Linux.
  