Improve constant element index access code generation

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index df4d8fc99c650a0192a8782db7cbf302e311802e..6eece777a17fc0c141f6e3155f71375ce137390e 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -5864,7 +5864,8 @@ HInstruction* HGraphBuilder::BuildUncheckedMonomorphicElementAccess(
   } else {
     length = AddInstruction(new(zone()) HFixedArrayBaseLength(elements));
   }
-  checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
+  checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length,
+                                                        ALLOW_SMI_KEY));
   return BuildFastElementAccess(elements, checked_key, val, mapcheck,
                                 map->elements_kind(), is_store);
 }