This firstly prints debug messages which show how bitbake decided to resolve
the virtual/xxx providers which is useful for debugging.
If the siggen has a tasks_resolved() method, it calls this, passing in
the mappings, allowing that to do things with the resolved names.
(Bitbake rev: d473fc84acddfd69a7207affcd89f65ea2ecf730)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>