libs/libc/misc/Make.defs: For platforms whose CPP tool does not support a variable number arguments to pre-processor macros, we may still need to build the debug functions even when CONFIG_DEBUG_FEATURES is not selected. For example, __alert() may be needed is CONFIG_ARCH_STACKDUMP is set.
configs/makerlisp: Add an sdboot configuration that will load .hex files from the SD card.
