[patch, libgfortran] Fix m4 file generation

[Thomas Koenig]

[To FX]

> With your patch, I get the following error:

> m4 -Dfile=generated/_abs_c4.F90 -I../../../../trunk2/libgfortran/m4 specific.m4 > generated/_abs_c4.F90
> /bin/sh: generated/_abs_c4.F90: No such file or directory

This is exceedingly strange.  My patch didn't touch that particular
line in Makefile.am, precicely because I got that error when I
removed $(srcdir).

Did the version before the patch work for you?

> I can't understand why, is it working for you?

I suspect some difference in interpretation of patsubst in line
601 in Makefile.am (possibly due to a difference in make versions).
Mine is

$ make -v
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for i486-pc-linux-gnu

	Thomas