isnan, isinf in ldc; Was: Re: Release imminent

[Danny Milosavljevic]

> And to repair your remaining, not building favourite packages - for instance
> bio packages with disappeared source...
>    http://hydra.gnu.org/eval/109040#tabs-still-fail

ldc fails because they do

  ::isnan

which is a bad idea if isnan is a C macro (which it usually isn't - but hey 
O_o). I've substituted

  isnan

for it and this part then compiles fine.

This fix is not safe in general because if there's a method called isnan in 
scope, it will use that. In the ldc case, they've named the method "isNan" - so 
it's fine.