#908 rmda- marking messages as prohibiting serialization

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

  The RdmaData/RdmaType messages were previously shown to be
  trivially byte-copyable to NVCC via a static assert.

src/vt/rdmahandle/manager.impl.h

@@ -76,6 +76,8 @@ struct HandleData {
 
 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))
@@ -84,6 +86,8 @@ 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,