It's a well known old saying, present in pretty much all languages and cultures I'm aware of, meaning exactly that one would be angry or/and upset, had one been alive today to witness whatever the saying relates to.
Only the proper way would be saying "rolls over in his grave", not spins, but, I guess, it's a 'postmodern' intensification.
In slavic languages it literally translates "turns over in his coffin", but basically the same thing.