Add Error message when missing dictionary for STL collection.

Issues an error message when we are missing the compiled
STL collection proxy for the data member of compiled class.

Error in <TStreamerInfo::Build>: The class "Container" is compiled and for its the data member "fList", we do not have a dictionary for the collection "list<Inside>", we will not be able to read or write this data member.
(cherry picked from v5-34-00-patches
 commit 80cf626f)

io/io/src/TStreamerInfo.cxx

@@ -386,6 +386,13 @@ void TStreamerInfo::Build()
             element = new TStreamerSTLstring(dmName, dmTitle, offset, dmFull, dmIsPtr);
          } else if (dm->IsSTLContainer()) {
             element = new TStreamerSTL(dmName, dmTitle, offset, dmFull, dm->GetTrueTypeName(), dmIsPtr);
+            if (fClass->IsLoaded()) {
+               if (!element->GetClassPointer()->IsLoaded()) {
+                  Error("Build","The class \"%s\" is compiled and for its the data member \"%s\", we do not have a dictionary for the collection \"%s\", we will not be able to read or write this data member.",GetName(),dmName,element->GetClassPointer()->GetName());
+                  delete element;
+                  continue;
+               }
+            }
          } else {
             TClass* clm = TClass::GetClass(dmType);
             if (!clm) {
@@ -1453,6 +1460,15 @@ void TStreamerInfo::BuildOld()
             offset = GetDataMemberOffset(dm, streamer);
             element->SetOffset(offset);
             element->Init(this);
+            // We have a loaded class, let's make sure that if we have a collection
+            // it is also loaded.
+            TClass *elemCl = element->GetClassPointer();
+            if (elemCl && elemCl->GetCollectionProxy() && !elemCl->IsLoaded()) {
+               Error("BuildOld","The class %s is compiled and for its data member %s, we do not have a dictionary for the collection '%s', we will not be able to read or write this data member.",GetName(),element->GetName(),element->GetClassPointer()->GetName());
+               offset = kMissing;
+               element->SetOffset(kMissing);
+               element->SetNewType(-1);
+            }
             element->SetStreamer(streamer);
             int narr = element->GetArrayLength();
             if (!narr) {