The thing that bothers me the most when I see something like that is not the yelling, but the stares of other shoppers who do not understand. In this case, the parent/caretaker was doing the best he could to calm this child down. Parents with autism may already understand this, but I am going to say it anyway: if your child is making a fuss in the supermarket, please understand that he or she does not mean to draw attention to you in a way that makes you feel uncomfortable. He or she probably doesn't even realize how loud they are yelling. These are just physical responses to sensory overload.
This is not always preventable and I cannot give individual advice in situations like that. My own sensory issues are not this severe. The only advice I can give is to stay as calm as possible and shop as quickly as possible, because, although your child cannot always articulate what they are feelings, all they want is to get out of the store, away from all the activity that is hurting their senses.
I wish everyone the best of luck in their holiday preparations!