validate failures

[Edward Z. Yang]

I've reverted the patch.

Excerpts from Simon Marlow's message of Wed Apr 06 06:26:15 -0400 2011:
> Questions:
> 
>   - did you validate Edward?

No. I thought it would be a safe patch because it only affected debugging,
and had the validate running over the evening. My apologies.

>   - why did we not get an email sent to cvs-ghc for this patch?
>     (there have been lots of missing emails from various people)

Dunno here.

Edward