remove 3 redundant casts in Objects/longobject.c

[orenmn]

ISTM that it's quite obvious that the (unsigned long) and the (unsigned long long) casts are redundant.

the (twodigits) cast is also redundant, because casting has precedence over shift left (as can be seen in http://en.cppreference.com/w/c/language/operator_precedence).

Just in case, I ran the test module on my Windows 10, with and without the patch, and as expected, it seems the patch doesn't break anything.

[mention-bot]

@orenmn, thanks for your PR! By analyzing the history of the files in this pull request, we identified @loewis, @Haypo, @mdickinson, @serhiy-storchaka and @tim-one to be potential reviewers.

[vstinner]

the (twodigits) cast is also redundant, because casting has precedence over shift left (as can be seen in http://en.cppreference.com/w/c/language/operator_precedence).

I don't understand your rationale, but the cast is redundant. thisone type is twodigits and it's casted to twodigits: useless cast.

[mdickinson]

LGTM. Thanks!