Replace SetObjectProperty / DefineObjectProperty with less powerful alternatives where relevant.

src/runtime/runtime-classes.cc

Index: src/runtime/runtime-classes.cc
diff --git a/src/runtime/runtime-classes.cc b/src/runtime/runtime-classes.cc
index 3dbcc65eca6af1e5e5e9a0f80009d18dd8a73640..fe76dfa0dd2564c9787cb9d806084cb74eea4f23 100644
--- a/src/runtime/runtime-classes.cc
+++ b/src/runtime/runtime-classes.cc
@@ -200,16 +200,8 @@ RUNTIME_FUNCTION(Runtime_DefineClassMethod) {
   CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 2);
 
-  uint32_t index;
-  if (name->AsArrayIndex(&index)) {
-    RETURN_FAILURE_ON_EXCEPTION(
-        isolate, JSObject::SetOwnElementIgnoreAttributes(object, index,
-                                                         function, DONT_ENUM));
-  } else {
-    RETURN_FAILURE_ON_EXCEPTION(
-        isolate, JSObject::SetOwnPropertyIgnoreAttributes(object, name,
-                                                          function, DONT_ENUM));
-  }
+  RETURN_FAILURE_ON_EXCEPTION(isolate, JSObject::DefinePropertyOrElement(
+                                           object, name, function, DONT_ENUM));
   return isolate->heap()->undefined_value();
 }