Use -cpp= for Fortran -cpp option passed to f951

[Joseph S. Myers]

On Thu, 29 Jul 2010, Richard Guenther wrote:

> Together with LTO we see issues when frontend specific arguments
> are passed down to lto1, like the fortran frontend -ffixed-* args
> which conflicts with the common -ffixed-X.  Like PRs 41844.
> Is there a chance, with your changes, to filter out all frontend
> handled options when generating COLLECT_GCC_OPTIONS?

If the required information is in the .opt files, no doubt it could be 
implemented, though I do not necessarily expect to convert everything 
using struct switchstr in gcc.c to use the same structures as the core 
compiler.

-- 
Joseph S. Myers
joseph@codesourcery.com