Fix a small but embarassing braino.

runtime/vm/intermediate_language.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 403 matching lines @@
     Value* current = env_use_list_;
     env_use_list_ = env_use_list_->next_use();
     current->set_definition(other);
     current->AddToEnvUseList();
   }
 }
 
 
 void Definition::ReplaceWith(Definition* other,
                              ForwardInstructionIterator* iterator) {
-  if ((iterator != NULL) && (other == iterator->Current())) {
+  if ((iterator != NULL) && (this == iterator->Current())) {
     iterator->ReplaceCurrentWith(other);
   } else {
     ReplaceUsesWith(other);
     ASSERT(other->env() == NULL);
     other->set_env(env());
     set_env(NULL);
     ASSERT(!other->HasSSATemp());
     if (HasSSATemp()) other->set_ssa_temp_index(ssa_temp_index());
 
     other->set_previous(previous());
@@ skipping 1162 matching lines @@
     value->set_use_index(i);
     value->AddToEnvUseList();
   }
   instr->set_env(copy);
 }
 
 
 #undef __
 
 }  // namespace dart