#908 rmda- marking messages as prohibitting serialization

- This should force the issue where NVCC appears to be attempting
  to serialization such messages.

src/vt/rdmahandle/manager.impl.h

@@ -85,6 +85,8 @@ static_assert( // that HandleData is trivially copyable
 
 template <typename T, HandleEnum E, typename ProxyT>
 struct ConstructMsg : vt::collective::ReduceTMsg<HandleData> {
+  vt_msg_serialize_prohibited();
+
   ConstructMsg() = default;
   explicit ConstructMsg(HandleData&& data)
     : vt::collective::ReduceTMsg<HandleData>(std::move(data))
@@ -93,6 +95,8 @@ struct ConstructMsg : vt::collective::ReduceTMsg<HandleData> {
 
 template <typename ProxyT, typename IndexT>
 struct InformRDMAMsg : vt::Message {
+  vt_msg_serialize_prohibited();
+
   InformRDMAMsg() = default;
   InformRDMAMsg(
     ProxyT in_proxy, RDMA_HandleType in_rdma_handle, bool uniform,