Kconfig files. Repartition some functionality. Bootloader support will need to be provided in logic under arch/z80/src/ez80 so the critical configuration selections were moved the Kconfig file there.
arch/z80/src/ez80/ez80_i2c.h: Rename arch/z80/src/ez80/ez80f91_i2c.h. It is sharable by both ez80f91 and ez80f92.
arch/z80/src/ez80/: Add logic to perform an additional level of interrupt redirection. This is necessary because the the interrupt handling is part of the loader FLASH-based logic. In order to share interrupts with the program loaded into RAM by the loader, another layer or redirection is required to get control to the interrupt handlers in the loaded program. See ez809f2_loader.asm and ez80f92_program.asm
boards/z80/ez80/z20x/scripts: Reduce size of the interrupt re-direction buffer from 1Kb to 512b.
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.
Squashed commit of the following:
libs/libxx: Fix some confusing in naming. If the directory is called libxx, then the library must be libxx.a (unless perhaps LIBCXX is selected).
libs/: Fix paths in moved library directories.
libs: Brute force move of libc, libnx, and libxx to libs. Cannot yet build it in that configuration.
