Add GetProperty/GetElement to JSReceiver and use it where possible

src/json-stringifier.h

Index: src/json-stringifier.h
diff --git a/src/json-stringifier.h b/src/json-stringifier.h
index d97ca2ba7374ec0b043bb36200702d3c32033d23..44e710375d43879a7f1b4dc10edc4d510343f532 100644
--- a/src/json-stringifier.h
+++ b/src/json-stringifier.h
@@ -501,8 +501,7 @@ BasicJsonStringifier::Result BasicJsonStringifier::SerializeJSArraySlow(
     if (i > 0) builder_.AppendCharacter(',');
     Handle<Object> element;
     ASSIGN_RETURN_ON_EXCEPTION_VALUE(
-        isolate_, element,
-        Object::GetElement(isolate_, object, i),
+        isolate_, element, JSReceiver::GetElement(isolate_, object, i),
         EXCEPTION);
     if (element->IsUndefined()) {
       builder_.AppendCString("null");
@@ -580,8 +579,8 @@ BasicJsonStringifier::Result BasicJsonStringifier::SerializeJSObject(
         DCHECK(key->IsNumber());
         key_handle = factory()->NumberToString(Handle<Object>(key, isolate_));
         if (key->IsSmi()) {
-          maybe_property = Object::GetElement(
-              isolate_, object, Smi::cast(key)->value());
+          maybe_property =
+              JSReceiver::GetElement(isolate_, object, Smi::cast(key)->value());
         } else {
           maybe_property = Object::GetPropertyOrElement(object, key_handle);
         }