[PATCH]: bump minimum MPFR version, (includes some fortran bits)

[Andreas Tobler]

Geoff Keating wrote:

> Does everyone really type --with-mpfr=.... on every build?  Looking at 
> gcc-testresults, I see:
> 
> Kaveh: yes
> Joey Ye: no
> HJ: no
> Guerby: yes
> Andreas Jaeger: no
> Dave Anglin: no
> Janis: yes
> Gerald Pfeifer: no
> Diego: yes
> Andreas Krebbel: no
> 
> It seems like mostly, anyone using the compiler farm has to use 
> --with-mpfr, and otherwise people avoid it.
> 

I'll have to add it as well on my sparc-solaris, hppa and x86_64-darwin 
builds, on my compile farm :)
On darwin-x86 I do not need it since they are placed in /usr/local.

Andreas