[wwwdocs,fortran] Update link to CHKSYS

[Gerald Pfeifer]

On Fri, 14 Apr 2017, Arjen Markus wrote:
> thanks for the suggestions - I agree that a download link which is
> more visible would be a good idea. I will adapt the pages with this 
> in mind.

Cool, thanks.

For the time being, I'm going ahead with the change below (taking
into consideration Jerry's recommendation to link one level higher)
since the link we currently show is broken.

I do believe it would be nice to have a specific link for your
"checking utilities" (as opposed to the wider, more general page),
and when/if you have one in place a short note would be great and
I'll happily update our page at https://gcc.gnu.org/readings.html
again.

Gerald

Index: readings.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/readings.html,v
retrieving revision 1.276
diff -u -r1.276 readings.html
--- readings.html	11 Apr 2017 22:30:59 -0000	1.276
+++ readings.html	15 Apr 2017 06:07:33 -0000
@@ -436,7 +436,7 @@
         possible to stress the compiler error handling.
       </li>
       <li>
-        <a href="http://ftp.cac.psu.edu/pub/ger/fortran/chksys.htm"><cite>Checking
+        <a href="http://flibs.sourceforge.net"><cite>Checking
         properties of the compiler and the run-time environment</cite></a> by
         Arjen Markus (source provided).
       </li>