| Index: src/runtime/runtime-classes.cc
 | 
| diff --git a/src/runtime/runtime-classes.cc b/src/runtime/runtime-classes.cc
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| index 37a5122cec3b6c0c6a2c5d45bc5768498340e930..303122fc3967c5f3abfc9a088885c958457aac98 100644
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| --- a/src/runtime/runtime-classes.cc
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| +++ b/src/runtime/runtime-classes.cc
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| @@ -91,7 +91,7 @@ static MaybeHandle<Object> DefineClass(Isolate* isolate,
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|    if (super_class->IsTheHole(isolate)) {
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|      prototype_parent = isolate->initial_object_prototype();
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|    } else {
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| -    if (super_class->IsNull()) {
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| +    if (super_class->IsNull(isolate)) {
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|        prototype_parent = isolate->factory()->null_value();
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|      } else if (super_class->IsConstructor()) {
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|        DCHECK(!super_class->IsJSFunction() ||
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| @@ -101,7 +101,8 @@ static MaybeHandle<Object> DefineClass(Isolate* isolate,
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|            Runtime::GetObjectProperty(isolate, super_class,
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|                                       isolate->factory()->prototype_string()),
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|            Object);
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| -      if (!prototype_parent->IsNull() && !prototype_parent->IsJSReceiver()) {
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| +      if (!prototype_parent->IsNull(isolate) &&
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| +          !prototype_parent->IsJSReceiver()) {
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|          THROW_NEW_ERROR(
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|              isolate, NewTypeError(MessageTemplate::kPrototypeParentNotAnObject,
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|                                    prototype_parent),
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| 
 |