build.llvm: including configure.llvm.inc must be optional
build.llvm: including configure.llvm.inc must be optional

veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi