gcc needs these forward declarations to get the ADL right, see

http://lists.boost.org/Archives/boost/2008/05/138134.php





[SVN r45950]

libs/spirit

@@ -1 +1 @@
-Subproject commit 1b0e5ccbf42e43e174daaff82eadd93afb5eeab8
+Subproject commit 98248488640bab32cc6e8a8c184c7c475420e8ca