Suppress a warning that's in the windows mobile system headers.

[SVN r57963]

test/exception/constructor_exception_tests.cpp

@@ -3,6 +3,8 @@
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
+#include "../helpers/prefix.hpp"
+
 #include "./containers.hpp"
 #include "../helpers/random_values.hpp"
 #include "../helpers/input_iterator.hpp"