Fix for issue #28287 (Illegal argument in isolate message : (object is a regular Dart Instance))

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index f43b12e8b86f480167ee3cc874ff84c99ce1f98f..74231572dea5b1bc1186e91c69fcd37791edfffc 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -702,6 +702,7 @@ class RawClass : public RawObject {
   friend class Object;
   friend class RawInstance;
   friend class RawInstructions;
+  friend class RawTypeArguments;
   friend class SnapshotReader;
   friend class InstanceSerializationCluster;
   friend class CidRewriteVisitor;
@@ -1701,6 +1702,7 @@ class RawType : public RawAbstractType {
   int8_t type_state_;
 
   friend class CidRewriteVisitor;
+  friend class RawTypeArguments;
 };