fix(dev-tools): fix show correct displayName with forwardRef in Dev Tools (#17613)

* fix(dev-tools): fix show correct displayName with forwardRef in Dev Tools

allow set `displayName` after `React.forwardRef()`,
makesure Dev Tools show displayName as same as `getWrappedName` in `shared/getComponentName.js`

* Removed a little unnecessary/redundant code.

* Fixed lint error (removed unused var)

Author: zthxxx

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

@@ -347,7 +347,7 @@ export function getInternalReactConstants(
 
   // NOTICE Keep in sync with shouldFilterFiber() and other get*ForFiber methods
   function getDisplayNameForFiber(fiber: Fiber): string | null {
-    const {elementType, type, tag} = fiber;
+    const {type, tag} = fiber;
 
     let resolvedType = type;
     if (typeof type === 'object' && type !== null) {
@@ -364,8 +364,10 @@ export function getInternalReactConstants(
       case IndeterminateComponent:
         return getDisplayName(resolvedType);
       case ForwardRef:
+        // Mirror https://github.com/facebook/react/blob/7c21bf72ace77094fd1910cc350a548287ef8350/packages/shared/getComponentName.js#L27-L37
         return (
-          resolvedType.displayName || getDisplayName(resolvedType, 'Anonymous')
+          (type && type.displayName) ||
+          getDisplayName(resolvedType, 'Anonymous')
         );
       case HostRoot:
         return null;
@@ -377,11 +379,7 @@ export function getInternalReactConstants(
         return null;
       case MemoComponent:
       case SimpleMemoComponent:
-        if (elementType.displayName) {
-          return elementType.displayName;
-        } else {
-          return getDisplayName(resolvedType, 'Anonymous');
-        }
+        return getDisplayName(resolvedType, 'Anonymous');
       case SuspenseComponent:
         return 'Suspense';
       case SuspenseListComponent: