Load elimination fix with a test case.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 89399db8e410724a5108f177031dd106ff45a4e8..e0f6921b4d969d7aeffa6920baa465e4e9a6d96b 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3575,7 +3575,8 @@ void HAllocate::CreateFreeSpaceFiller(int32_t free_space_size) {
   filler_map->FinalizeUniqueness();  // TODO(titzer): should be init'd a'ready
   filler_map->InsertAfter(free_space_instr);
   HInstruction* store_map = HStoreNamedField::New(zone, context(),
-      free_space_instr, HObjectAccess::ForMap(), filler_map);
+      free_space_instr, HObjectAccess::ForMap(), filler_map,
+      INITIALIZING_STORE);
   store_map->SetFlag(HValue::kHasNoObservableSideEffects);
   store_map->InsertAfter(filler_map);
 
@@ -3589,7 +3590,7 @@ void HAllocate::CreateFreeSpaceFiller(int32_t free_space_size) {
       HObjectAccess::ForJSObjectOffset(FreeSpace::kSizeOffset,
           Representation::Smi());
   HStoreNamedField* store_size = HStoreNamedField::New(zone, context(),
-      free_space_instr, access, filler_size);
+      free_space_instr, access, filler_size, INITIALIZING_STORE);
   store_size->SetFlag(HValue::kHasNoObservableSideEffects);
   store_size->InsertAfter(filler_size);
   filler_free_space_size_ = store_size;
@@ -3602,7 +3603,7 @@ void HAllocate::ClearNextMapWord(int offset) {
     HObjectAccess access = HObjectAccess::ForJSObjectOffset(offset);
     HStoreNamedField* clear_next_map =
         HStoreNamedField::New(zone, context(), this, access,
-            block()->graph()->GetConstant0());
+            block()->graph()->GetConstant0(), INITIALIZING_STORE);
     clear_next_map->ClearAllSideEffects();
     clear_next_map->InsertAfter(this);
   }