[gfortran] fortran preprocessing, round 2

[Andrew Pinski]

> This is an updated version of my patch taking care of warnings when cc1 
> is called from gfortran to preprocess fortran source. I used a 
> different (and in my view, cleaner) approach: Fortran options are not 
> marked as C, but when preprocessing fortran source, cc1 is given a 
> -lang-fortran flag, which makes the preprocessor not warning about use 
> of Fortran options.
> 
> Tested on i686-linux, with both languages=c and languages=c,fortran. 
> The current behaviour for compiling C and Fortran in a single 
> command-line is kept. Regtested for languages=c, regtesting in progress 
> for languages=c,fortran -- howdy, how long is that C testsuite to run! 
> :(

This looks like what I had in mind when I suggested this fix.

Thanks,
Andrew Pinski