[fortran,patch] Extend IEEE support to all real kinds

[FX]

> 2015-08-06  Uros Bizjak  <ubizjak@gmail.com>
> 
>    PR fortran/64022
>    * gfortran.dg/ieee/large_4.f90: New test.
> 
> Tested on x86_64-linux-gnu {,-m32}  and alphaev68-linux-gnu.
> OK for mainline?

OK. Thanks for the patch!

FX