NTDLL: Fix signed/unsigned comparison warnings

[Mike McCormack]

Dimitrie O. Paun wrote:

> Any gadge on if/when will be able to turn this warning on
> by default? How many warnings are currently left?

I'm compiling with this warning on at the moment and there's still loads 
of warnings.

It may be hard to clean up every warning without making the code messy 
(ie. using casts or intermediate variables).  Secondly, if we turn on 
the warning people may start "fixing" it the wrong way and hiding bugs.

So I think case it may be reasonable to just have a janitorial task to 
check and fix sign compare warnings warnings, but not turn on the 
warning in the CVS.

Mike