[elements] Add CreateFromArrayLike fast-path for JS_ARRAY_TYPE

src/elements.h

Index: src/elements.h
diff --git a/src/elements.h b/src/elements.h
index fc2e6a4fdbb09078c7fd2d383e44306e82a2cdf9..8a3be099e27e191b449008a681f96c1d66cc1c8d 100644
--- a/src/elements.h
+++ b/src/elements.h
@@ -175,6 +175,9 @@ class ElementsAccessor {
                             ElementsKind source_kind,
                             Handle<FixedArrayBase> destination, int size) = 0;
 
+  virtual Handle<FixedArray> CreateListFromArrayLike(Isolate* isolate,

[Jakob Kummerow, 2016/11/24 10:55:16]

nit: bit of a misnomer. Since it takes a JSArray (and not any JSObject with a
"length" property), it should be called "CreateListFromArray".

[Camillo Bruni, 2016/11/24 14:02:00]

ack.

+                                                     Handle<JSArray> array) = 0;
+
  protected:
   friend class LookupIterator;