[Ur] introducing a name in functor body

[Adam Chlipala]

Gergely Buday wrote:
>> I don't understand the question.  As I said, the full set of constant field
>> names exists in every context without declaration.
>>      
> But I get
>
>      Unbound constructor variable iter
>
> for augmenting a record type definition with
>
>      iter = int
>
> The code compiles without this addition.
>    

Constant record field names are capitalized.