mathlib

5bee8262 - feat(data/int/gcd): some missing lemmas about int.gcd (#6212)

feat(data/int/gcd): some missing lemmas about int.gcd (#6212) As requested [on zulip](https://leanprover.zulipchat.com/#narrow/stream/217875-Is-there.20code.20for.20X.3F/topic/different.20gcd's.3F/near/226203698).