I have tried to make compilation dependent on automatically generated files
(e.g. Makefile.flags) to make sure that the code gets rebuilt if we
This is, however, not possible with the suffix implicit rules. Moreover this
types of rules are long obsolete
The way how to handle this feature is to use pattern implicit rules which
seem to be much simpler to use and they can contain dependencies.
Makefile.rules.in now contains REBUILD_FORCE_FILES which contains all files
which should trigger rebuild. Each Makefile which includes Makefile.rules
can additionally add some extra files via EXTRA_REBUILD_FORCE_FILES.