Avoid runtimeType.toString in describeIdentity (#49087)

packages/flutter/lib/src/foundation/diagnostics.dart

@@ -9,6 +9,7 @@ import 'package:meta/meta.dart';
 import 'assertions.dart';
 import 'constants.dart';
 import 'debug.dart';
+import 'object.dart';
 
 // Examples can assume:
 // int rows, columns;
@@ -2962,7 +2963,7 @@ String shortHash(Object object) {
 ///    distinguish instances of the same class (hash collisions are
 ///    possible, but rare enough that its use in debug output is useful).
 ///  * [Object.runtimeType], the [Type] of an object.
-String describeIdentity(Object object) => '${object.runtimeType}#${shortHash(object)}';
+String describeIdentity(Object object) => '${objectRuntimeType(object, '<optimized out>')}#${shortHash(object)}';
 
 // This method exists as a workaround for https://github.com/dart-lang/sdk/issues/30021
 /// Returns a short description of an enum value.