C++ definitions are numerous, and they shouldn't pollute variable space and
performance outside of directories containing C++ files. This commit pushes
them into a defs-cpp.mk file.
Signed-off-by: Jan Lindemann <jan@janware.com>
dev-utils.mk is meant to provide targets like install-to-system,
which will be invoked during development
Signed-off-by: Jan Lindemann <jan@janware.com>