HStoreKeyed for Smis optimized for x64 + related redundant moves of elements removed

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 61e98b2b0ce9c0053c131098bd74d30a4cc15c2f..4dbfeaf0ea37c51202b24178901a6d788adc3c3d 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -1272,7 +1272,8 @@ class HGraphBuilder {
                                     ElementsKind kind,
                                     HValue* length,
                                     HValue* key,
-                                    bool is_js_array);
+                                    bool is_js_array,
+                                    bool is_store);
 
   HValue* BuildCopyElementsOnWrite(HValue* object,
                                    HValue* elements,