Work in progres, please take a look and give early feedback if this is the way we want to structure…

src/vm/session.cc

Index: src/vm/session.cc
diff --git a/src/vm/session.cc b/src/vm/session.cc
index 74b3d132b5b2436fd1eb5401634952f51f48f95d..dfe08655a1a7cd67b339530a191111067e1fbbe7 100644
--- a/src/vm/session.cc
+++ b/src/vm/session.cc
@@ -766,12 +766,19 @@ void Session::PushBuiltinClass(Names::Id name, int fields) {
     klass = program()->coroutine_class();
   } else if (name == Names::kPort) {
     klass = program()->port_class();
-  } else if (name == Names::kForeign) {
-    klass = program()->foreign_class();
+  } else if (name == Names::kForeignMemory) {
+    klass = program()->foreignmemory_class();
+  } else if (name == Names::kForeignFunction) {
+    klass = program()->foreignfunction_class();
   } else {
+    printf("name: %d, %d", name, Names::kForeignFunction);
     UNREACHABLE();
   }
 
+  if (!(klass->instance_format().type() != InstanceFormat::INSTANCE_TYPE ||
+       klass->NumberOfInstanceFields() == fields)) {
+    printf("Numberof fields: %d %d",  klass->NumberOfInstanceFields(), fields);
+  }
   ASSERT(klass->instance_format().type() != InstanceFormat::INSTANCE_TYPE ||
          klass->NumberOfInstanceFields() == fields);