[Ur] very long error messages

[Adam Chlipala]

Adam Chlipala wrote:
> Gergely Buday wrote:
>> on a large program I got an error message of almost 180 thousand lines.
>>
>> 0:0-0:0: Some constructor unification variables are undetermined in 
>> declaration
>> (look for them as "<UNIF:...>")
>>
>> It seemed to be too difficult to figure out what the problem is, but
>> then a simple search for UNIF showed me a function, for which
>> supplying a return type solved the problem.
>>
>> I suggest that the compiler should trim down the output to the
>> functions in which those UNIF variables are present. Adam, what do you
>> think of this?

I've just pushed a changeset that shrinks these messages.  What do you 
think of the new messages?  (Is it easy to recreate the case that led 
you to suggest this change?)