Add stress-tests to catch potential integer overflows

[Ngalstyan4]

We should have a methodical way of catching all the places where the wrong-sized variable is used (e.g. int in place of int64)
Inspiration: #186

[ezra-varady]

This feels like some sort of property based testing might be a good fit. Google's fuzztest is one interesting option. It might take a bit of work to get things set up but I think it's appealing long term for discovering these sorts of issues