Fix AC_FC_LIBRARY_LDFLAGS detection for BlueGene xlf -qipa.

[Ralf Wildenhues]

Without this patch, links using the $FCLIBS set by AC_FC_LIBRARY_LDFLAGS
will fail when the user has enabled inter procedural analysis with the
XL Fortran compiler; tested on BlueGene.

I'm not aware of any libink that might be relevant in the area of
compiler support libraries, but you never know, of course.

Thanks,
Ralf

    Fix AC_FC_LIBRARY_LDFLAGS detection for BlueGene xlf -qipa.
    
    * lib/autoconf/fortran.m4 (_AC_FC_LIBRARY_LDFLAGS): Ignore
    '-link', added spuriously when -qipa is used with the XL
    Fortran compilers on BlueGene.

diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
index 8f64976..8f84f30 100644
--- a/lib/autoconf/fortran.m4
+++ b/lib/autoconf/fortran.m4
@@ -638,7 +638,7 @@ while test address@hidden:@] != 1; do
          ;;
          # Ignore these flags.
        -lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \
-         |-LANG:=* | -LIST:* | -LNO:*)
+         |-LANG:=* | -LIST:* | -LNO:* | -link)
          ;;
        -lkernel32)
          test x"$CYGWIN" != xyes && 
ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_arg"