Extra tests workaround for the new serie

I've uploaded 4.14.2 to experimental without those workarounds we currently carry in Ubuntu. I think those are suboptimal and the 32 bits issue is probably something should be fixed instead of ignored but those architectures aren't considered supported upstream and not a desktop target for Ubuntu and we don't have more resources to spend on those on the Ubuntu side at the moment. Unsure if we want to do the same in Debian but I'm at least pushing to get some feedback maybe from @smcv and @jbicha