RFA: Support infinity, NaN, and denormalized numbers in floatformat.c

[DJ Delorie]

> 2003-12-03  Ian Lance Taylor  <ian@wasabisystems.com>
> 
> 	* floatformat.c: Include "config.h" and <string.h> if available.
> 	(INFINITY, NAN): Define if not defined by <math.h>.
> 	(floatformat_to_double): Handle NaN, infinity, and denormalized
> 	numbers.
> 	(floatformat_from_double): Likewise.
> 	(ieee_test): In debugging code, use little endian rather than big
> 	endian.  Correct tests to handle NaN and to check correct sign of
> 	zero.  Omit m68k extended test.
> 	(main): Add more debugging cases.

Ok.