add offscreen state node (#24026)

Add state node on Offscreen fibers with id (in preparation for transition tracing)

Author: lunaruan

packages/react-reconciler/src/ReactFiber.new.js

@@ -15,7 +15,10 @@ import type {WorkTag} from './ReactWorkTags';
 importtype{TypeOfMode}from'./ReactTypeOfMode';
 importtype{Lanes}from'./ReactFiberLane.new';
 importtype{SuspenseInstance,Props}from'./ReactFiberHostConfig';
-importtype{OffscreenProps}from'./ReactFiberOffscreenComponent';
+importtype{
+OffscreenProps,
+OffscreenInstance,
+}from'./ReactFiberOffscreenComponent';
 
 import{
 createRootStrictEffectsByDefault,
@@ -735,6 +738,8 @@ export function createFiberFromOffscreen(
 constfiber=createFiber(OffscreenComponent,pendingProps,key,mode);
 fiber.elementType=REACT_OFFSCREEN_TYPE;
 fiber.lanes=lanes;
+constprimaryChildInstance: OffscreenInstance={};
+fiber.stateNode=primaryChildInstance;
 returnfiber;
 }
 

packages/react-reconciler/src/ReactFiber.old.js

@@ -15,7 +15,10 @@ import type {WorkTag} from './ReactWorkTags';
 importtype{TypeOfMode}from'./ReactTypeOfMode';
 importtype{Lanes}from'./ReactFiberLane.old';
 importtype{SuspenseInstance,Props}from'./ReactFiberHostConfig';
-importtype{OffscreenProps}from'./ReactFiberOffscreenComponent';
+importtype{
+OffscreenProps,
+OffscreenInstance,
+}from'./ReactFiberOffscreenComponent';
 
 import{
 createRootStrictEffectsByDefault,
@@ -735,6 +738,8 @@ export function createFiberFromOffscreen(
 constfiber=createFiber(OffscreenComponent,pendingProps,key,mode);
 fiber.elementType=REACT_OFFSCREEN_TYPE;
 fiber.lanes=lanes;
+constprimaryChildInstance: OffscreenInstance={};
+fiber.stateNode=primaryChildInstance;
 returnfiber;
 }
 

packages/react-reconciler/src/ReactFiberOffscreenComponent.js

@@ -31,3 +31,5 @@ export type OffscreenState = {|
 baseLanes: Lanes,
 cachePool: SpawnedCachePool|null,
 |};
+
+exporttypeOffscreenInstance={};