Added test case for existing bind<void> support.

test/Jamfile.v2

@@ -28,6 +28,7 @@ test-suite "bind"
       [ run bind_placeholder_test.cpp ]
       [ run bind_rvalue_test.cpp ]
       [ run bind_and_or_test.cpp ]
+      [ run bind_void_test.cpp ]
       [ run mem_fn_test.cpp ]
       [ run mem_fn_void_test.cpp ]
       [ run mem_fn_derived_test.cpp ]