ENH: IOobject: make registerObject flag accessible

src/OpenFOAM/db/IOobject/IOobject.H

@@ -275,6 +275,12 @@ public:
                 name_ = newName;
             }
 
+            //- Register object created from this IOobject with registry if true
+            bool& registerObject()
+            {
+                return registerObject_;
+            }
+
             //- Register object created from this IOobject with registry if true
             bool registerObject() const
             {