Guard against non-sensical ReadyToRunGenericHelperNode (#99513)

Author: MichalStrehovsky

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ReadyToRunGenericHelperNode.cs

@@ -39,6 +39,9 @@ public bool HandlesInvalidEntries(NodeFactory factory)
 
         public ReadyToRunGenericHelperNode(NodeFactory factory, ReadyToRunHelperId helperId, object target, TypeSystemEntity dictionaryOwner)
         {
+            Debug.Assert(
+                (dictionaryOwner is TypeDesc type && type.HasInstantiation)
+                || (dictionaryOwner is MethodDesc method && method.HasInstantiation));
             _id = helperId;
             _dictionaryOwner = dictionaryOwner;
             _target = target;