Simple bugfix in reaching definitions.

src/data-flow.cc

 // Copyright 2010 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 1909 matching lines @@
   ASSERT(!IsMarkedWith(mark));
   int instruction_count = instructions_.length();
   int variable_count = variables->length();
 
   rd_.Initialize(definition_count);
 
   for (int i = 0; i < instruction_count; i++) {
     Expression* expr = instructions_[i]->AsExpression();
     if (expr == NULL) continue;
     Variable* var = expr->AssignedVar();
-    if (var == NULL) continue;
+    if (var == NULL || !var->IsStackAllocated()) continue;
 
     // All definitions of this variable are killed.
     BitVector* def_set =
         variables->at(ReachingDefinitions::IndexFor(var, variable_count));
     rd_.kill()->Union(*def_set);
 
     // All previously generated definitions are not generated.
     rd_.gen()->Subtract(*def_set);
 
     // This one is generated.
@@ skipping 169 matching lines @@
   // all necessary successors to the worklist.
   while (!worklist.is_empty()) {
     Node* node = worklist.Remove();
     node->MarkWith(!mark);
     node->UpdateRDIn(&worklist, mark);
   }
 }
 
 
 } }  // namespace v8::internal