wip: fix render fn compat detection

packages/runtime-dom/src/components/Transition.ts

@@ -46,6 +46,10 @@ export const Transition: FunctionalComponent<TransitionProps> = (
 
 Transition.displayName = 'Transition'
 
+if (__COMPAT__) {
+  Transition.__isBuiltIn = true
+}
+
 const DOMTransitionPropsValidators = {
   name: String,
   type: String,

packages/runtime-dom/src/components/TransitionGroup.ts

@@ -22,7 +22,8 @@ import {
   SetupContext,
   toRaw,
   compatUtils,
-  DeprecationTypes
+  DeprecationTypes,
+  ComponentOptions
 } from '@vue/runtime-core'
 import { extend } from '@vue/shared'
 
@@ -39,7 +40,7 @@ export type TransitionGroupProps = Omit<TransitionProps, 'mode'> & {
   moveClass?: string
 }
 
-const TransitionGroupImpl = {
+const TransitionGroupImpl: ComponentOptions = {
   name: 'TransitionGroup',
 
   props: /*#__PURE__*/ extend({}, TransitionPropsValidators, {
@@ -145,6 +146,10 @@ const TransitionGroupImpl = {
   }
 }
 
+if (__COMPAT__) {
+  TransitionGroupImpl.__isBuiltIn = true
+}
+
 /**
  * TransitionGroup does not support "mode" so we need to remove it from the
  * props declarations, but direct delete operation is considered a side effect