Implement HChange support for Smis and use it in Load/StoreNameField

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 4381 matching lines @@
     for (HInstruction* current = blocks_[i]->first();
          current != NULL;
          current = current->next()) {
       if (current->IsChange()) {
         HChange* change = HChange::cast(current);
         // Propagate flags for negative zero checks upwards from conversions
         // int32-to-tagged and int32-to-double.
         Representation from = change->value()->representation();
         ASSERT(from.Equals(change->from()));
         if (from.IsInteger32()) {
-          ASSERT(change->to().IsTagged() || change->to().IsDouble());
+          ASSERT(change->to().IsTagged() ||
+                 change->to().IsDouble() ||
+                 change->to().IsSmi());
           ASSERT(visited.IsEmpty());
           PropagateMinusZeroChecks(change->value(), &visited);
           visited.Clear();
         }
       }
     }
   }
 }
 
 
@@ skipping 8056 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal