xml/manual/debug_mode.xml reference to Namespace Association

[Gerald Pfeifer]

I found that xml/manual/debug_mode.xml has a reference to the
following http://gcc.gnu.org/onlinedocs/gcc/Namespace-Association.html 
in

  <para>Achieving link- and run-time coexistence is not a trivial
    implementation task. To achieve this goal we required a small
    extension to the GNU C++ compiler (since incorporated into the C++11 
    language specification, described in the GCC Manual for the C++ language as
    <link xmlns:xlink="http://www.w3.org/1999/xlink" 
    xlink:href="http://gcc.gnu.org/onlinedocs/gcc/Namespace-Association.html#Namespace-Association">namespace
    association</link>), and a complex organization of debug- and
    release-modes. The end result is that we have achieved per-use
    recompilation but have had to give up some checking of the
    <code>std::basic_string</code> class template (namely, safe
    iterators).
  </para>

That link is broken, and I could not find any suitable replacement
in the GCC documentation.  

Any hints?  Suggestions how to go about this?  (Perhaps simply omit
the first half of that sentence?)

Gerald