Deprecate non-standard Array methods and clarify Object::isArray

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index a0b75eb1cd6b96fec38d9cf64d40dcb18e7e4d2f..9078b4d7240fe5bf8059de8dba2bcca23e52a108 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6204,10 +6204,7 @@ MaybeLocal<Object> Array::CloneElementAt(Local<Context> context,
 }
 
 
-Local<Object> Array::CloneElementAt(uint32_t index) {
-  auto context = ContextFromHeapObject(Utils::OpenHandle(this));
-  RETURN_TO_LOCAL_UNCHECKED(CloneElementAt(context, index), Object);
-}
+Local<Object> Array::CloneElementAt(uint32_t index) { return Local<Object>(); }
 
 
 Local<v8::Map> v8::Map::New(Isolate* isolate) {