(CFACT-151) Add path fact

Hmm, that's a good point about gce/ec2. I was thinking of them as linux only, but that's not correct. I mean AIX will never resolve them but it would also bail immediately b/c of the virtualization check.

Yeah, I can see why we ditched `add_common_facts` but now that we actually *have* some meaningful ones, it would save some copy-pasta (and the possibility of forgetting a platform).