It's very common slang; and, like a lot of slang, vivid and rich in meaning: somewhat lower-class, thoroughly unsuitable for any formal setting, to be avoided at all costs by people who are learning English, but indispensable in literature and even life, depending on where you find yourself.
isn't "I ain't got no shoes" double negative then?
Yes. English is a melting pot of languages. In many languages, double negatives are good grammar because they agree.
So double negatives have thoroughly infiltrated English in every country, even though they make no sense in our grammar: Two wrongs don't make a right, two rights don't make a left, and two negatives don't make a positive.