Language either has a standard that defines what the language is (and isn't), or it has something similar to a standard (which makes the definition more vague). In either case, there will be some sort of a document accepted by the majority of the language users that states what is and isn't the language.

If the language's document states that the language has arbitrary precision operations, then the authors of the language are free to implement it however way they want, let it be monkeys with abacus, it's still part of the language.