Fix for PR 15235 libgfortran doesn't build on Solaris

[Tobias Schlüter]

Paul Brook wrote:
>>2004-05-15  Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>
>>
>>	* io/write.c (write_float): Check for finite(), adapt tests.
> 
> 
> This is ok if it does solve the problem. You should also add a comment saying 
> why we use finite, not isinf.

I should have looked closer. Stupid me. Please don't look at the 
surrounding code :-) I retract that patch.

Rainer, what are the ways to check for NaN on Solaris? From what I see 
on the SunOS box I have access to, isnan is in math.h, and is therefore 
available on all systems. Is that right?

- Tobi