unix, genunix partial warning cleanup
While going through and doing some development work, I have gone through and taken a pass through a number of warnings that were gagged in unix and genunix which genuinely make building harder. While things aren't 100% clean, this has been sitting around long enough that it's worth going through and getting back. While this is all being put back as one commit, the assosciated review has the individual changes for things that should make it easier for this to be reviewed if preferred. Due to the testing and risk here, I've tried to combine that into a large chunk.
In particular, to test this on debug bits I went through and ran through the following test suites to try and build up confidence (along with some basic use myself):