Yeah, I retract my "technically not born" comment. I don't think there is a single widely agreed upon technical definition and, if there was, I'm not sure it would be relevant. Interesting, though, that the date of death might be before the date of birth.
Almost all of the genealogy I do is pre-1900. I'm not sure I've ever encountered a record referring to a stillborn child, although it's quite possible that they were recorded as being born and dying the same day. Basically, if there was info about a child, I would include it.
Re the original question - The existence of burial records is pretty irrelevant. If date/place of burial is not known, there is no problem with not having them.