[Review]: Fix Integer Division Expansion special case of divide by 1

[Aditya Nandakumar]

The problem is the check is a special case for handling X/1 - even if the special case is not being used, the expansion into the loop should still produce a valid quotient. It would be hard to test before and after for correctness.
The problem with the out of tree target is likely in the codegen of the expansion into the loop - and changing the special case of divide by 1 only fixes that case.
> On Jul 6, 2015, at 4:35 PM, Michael Ilseman <milseman at apple.com> wrote:
> 
> Then can you sanitize and commit such a test case?
> 
>> On Jul 6, 2015, at 4:26 PM, Aditya Nandakumar <aditya_nandakumar at apple.com> wrote:
>> 
>> I don’t have a test case before and after for in-tree target but it fixed test for out of tree target.
>> The logic is what I am pointing out is wrong - we need to check if CTLZ(divisor) == Num_bits - 1 rather than CTLZ(divisor) - CTLZ(dividend).
>>> On Jul 6, 2015, at 2:29 PM, Michael Ilseman <milseman at apple.com> wrote:
>>> 
>>> Do you have a test case that demonstrates the failure before-hand, and the fix after? 
>>> 
>>>> On Jul 2, 2015, at 12:26 PM, Aditya Nandakumar <aditya_nandakumar at apple.com> wrote:
>>>> 
>>>> <DiffIntUnsignedDivision.patch>
>>> 
>> 
>