Do you know anyone else using solaris who could do a review (ie: confirm that your patch makes sense and works for them)?  It looks like jcea, who is our only current committer who uses Solaris as far as I know (well, OpenIndiana), hasn't had time to look at this.

On the other hand, it isn't 100% clear to me that this is appropriate.  I'm not (yet) experienced enough with the internals of our build system to be the one to make the call, but it seems to me that you can support -z ignore by modifying your Modules/Setup file, so it may not be appropriate to inject solaris specific support in setup.py for an option that isn't normally used.