feat[ReactFabricPrivateInterface]: add getInternalInstanceHandleFromPublicInstance (facebook#41786)

Summary:

Changelog: [Internal]

This is the preprequisite for facebook/react#27783

Reviewed By: rubennorte

Differential Revision: D51808831

Author: Ruslan Lesiutin

packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactFabricPublicInstance.js

@@ -8,6 +8,11 @@
  * @flow strict-local
  */
 
+/**
+ * This module is meant to be used by the React renderers to create public
+ * instances and get some data from them (like their instance handle / fiber).
+ */
+
 import type ReactNativeElement from '../../DOM/Nodes/ReactNativeElement';
 import type ReadOnlyText from '../../DOM/Nodes/ReadOnlyText';
 import typeof ReactFabricType from '../../Renderer/shims/ReactFabric';
@@ -79,3 +84,9 @@ export function getNodeFromPublicInstance(
     publicInstance.__internalInstanceHandle,
   );
 }
+
+export function getInternalInstanceHandleFromPublicInstance(
+  publicInstance: ReactFabricHostComponent | ReactNativeElement,
+): InternalInstanceHandle {
+  return publicInstance.__internalInstanceHandle;
+}

packages/react-native/Libraries/ReactPrivate/ReactNativePrivateInterface.js

@@ -19,6 +19,7 @@ import typeof CustomEvent from '../Events/CustomEvent';
 import typeof {
   createPublicInstance,
   createPublicTextInstance,
+  getInternalInstanceHandleFromPublicInstance,
   getNativeTagFromPublicInstance,
   getNodeFromPublicInstance,
 } from '../ReactNative/ReactFabricPublicInstance/ReactFabricPublicInstance';
@@ -108,4 +109,8 @@ module.exports = {
     return require('../ReactNative/ReactFabricPublicInstance/ReactFabricPublicInstance')
       .getNodeFromPublicInstance;
   },
+  get getInternalInstanceHandleFromPublicInstance(): getInternalInstanceHandleFromPublicInstance {
+    return require('../ReactNative/ReactFabricPublicInstance/ReactFabricPublicInstance')
+      .getInternalInstanceHandleFromPublicInstance;
+  },
 };