ghc warnings messed up in 6.01

[Simon Marlow]

> Simon seems to have agreed that The Right Thing is to treat bindings
> with names beginning with an underscore as if they are used w.r.t. to
> the bindings they use (they're already treated as used w.r.t. warnings
> for themselves.)  With this enhancement (and the other warning fixes
> apparently already in HEAD), you should be able to change "ds" to
> "_ds" and get no warnings.
> 
> BTW (here's the real point of my message :-)), is this enchancement
> planned?  For when?  Thanks.

It won't be in 6.2, but hopefully in 6.4.

Cheers,
	Simon