Fix missing Smi check in grow mode keyed stores.

src/hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1337 matching lines @@
   if (is_store && IsFastSmiElementsKind(elements_kind) &&
       !val->type().IsSmi()) {
     AddInstruction(new(zone) HCheckSmi(val));
   }
 
   if (IsGrowStoreMode(store_mode)) {
     NoObservableSideEffectsScope no_effects(this);
 
     elements = BuildCheckForCapacityGrow(object, elements, elements_kind,
                                          length, key, is_js_array);
-    checked_key = key;
+    if (!key->type().IsSmi()) {
+      checked_key = AddInstruction(new(zone) HCheckSmiOrInt32(key));
+    } else {
+      checked_key = key;
+    }
   } else {
     checked_key = AddBoundsCheck(
         key, length, ALLOW_SMI_KEY, checked_index_representation);
 
     if (is_store && (fast_elements || fast_smi_only_elements)) {
       if (store_mode == STORE_NO_TRANSITION_HANDLE_COW) {
         NoObservableSideEffectsScope no_effects(this);
 
         elements = BuildCopyElementsOnWrite(object, elements, elements_kind,
                                             length);
@@ skipping 10503 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal