Don't replace initializing smi stores during store elimination.

src/hydrogen-store-elimination.cc

Index: src/hydrogen-store-elimination.cc
diff --git a/src/hydrogen-store-elimination.cc b/src/hydrogen-store-elimination.cc
index cf5f3a15e69822491cb8e0ebda685fd576223f95..bbb115a9b40dfb67935a2ec34bf7641cb3d430c9 100644
--- a/src/hydrogen-store-elimination.cc
+++ b/src/hydrogen-store-elimination.cc
@@ -58,7 +58,7 @@ void HStoreEliminationPhase::ProcessStore(HStoreNamedField* store) {
   while (i < unobserved_.length()) {
     HStoreNamedField* prev = unobserved_.at(i);
     if (aliasing_->MustAlias(object, prev->object()->ActualValue()) &&
-        store->access().Equals(prev->access())) {
+        prev->CanBeReplacedWith(store)) {
       // This store is guaranteed to overwrite the previous store.
       prev->DeleteAndReplaceWith(NULL);
       TRACE(("++ Unobserved store S%d overwritten by S%d\n",