[gfortran] Fix gfortran include problem

[François-Xavier Coudert]

> If it replicates g77 behavior, then it should be fine.

Well, it does, including the case you mention below.

> What I'm thinking about is a case where file.f is a
> symlink to tmp/fileA.f.  In tmp/ we have fileB.f such
> that fileA.f has "include fileB.f".  Will gfortran
> find fileB.f?

No, it won't. And I'm pretty sure we don't want it to find it, as it
is contrary to the (as far as I understood it) philosophy of symlinks.
Moreover, g77 and other compilers don't do it that way.

FX