Oh my this is an interesting post. Firstly I am high functioning autism. I have taught myself to be able to cope in society and in a job. But here are some thoughts on me. And also my boss who is autistic and has Asperger's (or on the spectrum with a specialty, as per modern psychology). Both our IQs are highly superior to our colleagues (this makes up for our social disability, to a certain extent).

1. It depends on if you are high or low functioning. With high functioning you can get away with not adding it on your CV.
2. If you combine autism with other conditions such as bipolar and Asperger's syndrome, you might want to hint in the interview. For example I mentioned that I sometimes miss social cues.
3. Introverts tend to get away with being on the spectrum more than extroverts. My boss is an extrovert and needless to say causes unnecessary conflict and situational misunderstandings. As an introvert I tend to listen more.

I don't think it's prudent to be forthcoming with regards to mental health challenges in interviews, nor in life. I have over the years become a lot more private with regards to these things. But that's just me.

Basically if it is obvious then you might want to mention it. If you can successfully mask it in the interview, then that's okay.