Add ASIO_WARN_MESSAGE for use in some linux-specific test code.

asio/src/tests/unit/socket_base.cpp

diff --git a/asio/src/tests/unit/socket_base.cpp b/asio/src/tests/unit/socket_base.cpp
index 8eaff05..db1e281 100644
--- a/asio/src/tests/unit/socket_base.cpp
+++ b/asio/src/tests/unit/socket_base.cpp
@@ -246,7 +246,7 @@
   // On Linux, only root can set SO_DEBUG.
   bool not_root = (ec == asio::error::access_denied);
   ASIO_CHECK(!ec || not_root);
-  BOOST_WARN_MESSAGE(!ec, "Must be root to set debug socket option");
+  ASIO_WARN_MESSAGE(!ec, "Must be root to set debug socket option");
 #else // defined(__linux__)
 # if defined(ASIO_WINDOWS) && defined(UNDER_CE)
   // Option is not supported under Windows CE.

asio/src/tests/unit/unit_test.hpp

diff --git a/asio/src/tests/unit/unit_test.hpp b/asio/src/tests/unit/unit_test.hpp
index 824d7bf..ab1257f 100644
--- a/asio/src/tests/unit/unit_test.hpp
+++ b/asio/src/tests/unit/unit_test.hpp
@@ -48,6 +48,9 @@
 #define ASIO_CHECK_MESSAGE(expr, message) \
   do { if (!(expr)) { std::cout << message << std::endl; assert(expr); } } while (0)
 
+#define ASIO_WARN_MESSAGE(expr, message) \
+  do { if (!(expr)) { std::cout << message << std::endl; } } while (0)
+
 #define ASIO_ERROR(message) assert(0 && message)
 
 #define ASIO_TEST_SUITE(name, tests) \
@@ -72,6 +75,8 @@
 
 #define ASIO_CHECK_MESSAGE(expr, msg) BOOST_CHECK_MESSAGE(expr, msg)
 
+#define ASIO_WARN_MESSAGE(expr, msg) BOOST_WARN_MESSAGE(expr, msg)
+
 #define ASIO_ERROR(expr) BOOST_ERROR(expr)
 
 #define ASIO_TEST_SUITE(name, tests) \