and send ints to igcd, too:

```
>>> timeit('igcd(int(S(randint(1,1000))),int(S(randint(1,1000))))','from sympy import S,igcd\nfrom random import randint',number=100000)
3.953987755223409
>>> timeit('igcd((S(randint(1,1000))),(S(randint(1,1000))))','from sympy import S,igcd\nfrom random import randint',number=100000)
5.708105832930926
```