Create code pattern for sanitizing signed integer class

[Alvov1]

Well, currently sanitizing is only performed on unsigned class. I couldn't quickly come up with a code pattern that would utilize the majority of signed integers functionality. It should be something like a long wandering sequence of integers greater than and less than zero with multiplication and division.

It's required to write code inside sanitize/signed/main.cpp + add additional job inside sanitize_multiple_platforms.yml