Add WORKAROUND style definitions for public use.

test/tested_at_outdated.cpp

@@ -0,0 +1,18 @@
+/*
+Copyright Rene Rivera 2011-2017
+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 <boost/predef/version_number.h>
+#define BOOST_DETECT_OUTDATED_WORKAROUNDS
+#include <boost/predef/other/workaround.h>
+
+int main()
+{
+#if BOOST_PREDEF_TESTED_AT(BOOST_VERSION_NUMBER(2,0,0),1,0,0)
+    return 1;
+#else
+    return 0;
+#endif
+}