Summer is here, which means reviving the contentious debate over whether or not a favorite ice cream topping’s name has racist origins. “I’ve heard them called jimmies ... It’s after Jim Crow,” said Carly Fishkin, 25, who grew up in Wellesley and prefers to call them sprinkles. Her nearby friend, Izak Shapiro, also 25, agreed. They are two of many who have heard that the word jimmies has deeply racist connotations.