Place pork in the slow cooker. In a mixing bowl, whisk together Coke, brown sugar, garlic, diced green chiles, tomato sauce, and taco seasoning. Pour over pork. Cook on low for about 8 hours or until the meat is easily shredded. Shred and place in a large bowl. Pour about ⅓ of a cup of the cooking liquid over the shredded pork and stir.