Thanks for the links. Both are useful, although it seems the discussion diverges quickly into generics. I can't really find the reason for why a separate package for these functions would be a bad idea.
I have my own package ints of course, so it doesn't really matter that much. It's just strange this is not present in the Go stdlib given its common use. It's weird when learning Go and still weird after two years of using it.
Having these function will probably also reduce the complaints about the lack of generics a bit.