Maybe there was something else there before, and it stopped working when they removed it, so they tried adding back the most minimal thing they could think of as a sanity check.

I don't think using noops to get the parser to co-operate is that strange at all, especially not something like a makefile where whitespace is significant. It's the whole point of the `pass` noop in python: the Python grammar expects there to be something inside a loop, so if you want an empty one, you have to throw a noop in there.