[Devtools] Look for a ReactMemoCacheSentinel on state (#28831)

The useMemoCache polyfill doesn't have access to the fiber, and it
simply uses state, which does not work with the existing devtools 
badge for the compiler.

With this PR, devtools will look on the very first hook's state for the
memo cache sentinel and display the Forget badge if present.

The polyfill will add this sentinel to it's state (the cache array).

Author: gsathya

packages/react-devtools-shared/src/backend/ReactSymbols.js

@@ -67,3 +67,7 @@ export const SUSPENSE_LIST_SYMBOL_STRING = 'Symbol(react.suspense_list)';
 
 export const SERVER_CONTEXT_DEFAULT_VALUE_NOT_LOADED_SYMBOL_STRING =
   'Symbol(react.server_context.defaultValue)';
+
+export const REACT_MEMO_CACHE_SENTINEL: symbol = Symbol.for(
+  'react.memo_cache_sentinel',
+);

packages/react-devtools-shared/src/backend/renderer.js

@@ -86,6 +86,7 @@ import {
   STRICT_MODE_SYMBOL_STRING,
   PROFILER_NUMBER,
   PROFILER_SYMBOL_STRING,
+  REACT_MEMO_CACHE_SENTINEL,
   SCOPE_NUMBER,
   SCOPE_SYMBOL_STRING,
   FORWARD_REF_NUMBER,
@@ -474,8 +475,12 @@ export function getInternalReactConstants(version: string): {
     }
 
     let resolvedContext: any = null;
-    // $FlowFixMe[incompatible-type] fiber.updateQueue is mixed
-    if (!shouldSkipForgetCheck && fiber.updateQueue?.memoCache != null) {
+    if (
+      !shouldSkipForgetCheck &&
+      // $FlowFixMe[incompatible-type] fiber.updateQueue is mixed
+      (fiber.updateQueue?.memoCache != null ||
+        fiber.memoizedState?.memoizedState?.[REACT_MEMO_CACHE_SENTINEL])
+    ) {
       const displayNameWithoutForgetWrapper = getDisplayNameForFiber(
         fiber,
         true,