distrooverrides.bbclass: DISTRO_FEATURES as overrides
This achieves the same goal as the same change to bitbake.conf itself,
but because the class gets added later as part expanding INHERIT, this
new approach is less likely to run into problems when DISTRO_FEATURES
contains complex code.
Another difference is that the class currently does not get inherited
by default and thus is completely absent from a build unless some
layer or include file adds it to INHERIT.
Compared to the earlier code in bitbake.conf and a similar class in
intel-iot-refkit, additional overrides now get sorted. This makes the
final OVERRIDES more deterministic.
The lessons learned about unintentionally depending on OVERRIDES are
documented in the class because such problems are more likely to show
up as unexpected signature differences when using this class.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
