Some files have been left in the build system, even though they are not used (anymore).

common/bin/boot_cycle.sh common/bin/compare-objects.sh is not needed anymore. The first was a crude replacement for the bootcycle-images target, and the second was only at use while the modern build system was developed.

common/autoconf/config.h.in and common/autoconf/spec.sh.in both generate files in the $BUILD top directory which is not used. config.h was never used at all, and spec.sh was support for compare-objects.sh.