Fixes a couple problems with GC of unoptimized code.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 6829 matching lines @@
     }
     return env->ValueAt(index);
   }
 
   intptr_t fixed_parameter_count() const {
     return fixed_parameter_count_;
   }
 
   const Function& function() const { return function_; }
 
+  const Code& code() const { return code_; }
+
   Environment* DeepCopy() const { return DeepCopy(Length()); }
 
   void DeepCopyTo(Instruction* instr) const;
   void DeepCopyToOuter(Instruction* instr) const;
 
   void PrintTo(BufferFormatter* f) const;
 
  private:
   friend class ShallowIterator;
 
   Environment(intptr_t length,
               intptr_t fixed_parameter_count,
               intptr_t deopt_id,
               const Function& function,
               Environment* outer)
       : values_(length),
         locations_(NULL),
         fixed_parameter_count_(fixed_parameter_count),
         deopt_id_(deopt_id),
         function_(function),
+        code_(Code::Handle(function.unoptimized_code())),
         outer_(outer) { }
 
   // Deep copy an environment.  The 'length' parameter may be less than the
   // environment's length in order to drop values (e.g., passed arguments)
   // from the copy.
   Environment* DeepCopy(intptr_t length) const;
 
   GrowableArray<Value*> values_;
   Location* locations_;
   const intptr_t fixed_parameter_count_;
   intptr_t deopt_id_;
   const Function& function_;
+  const Code& code_;
   Environment* outer_;
 
   DISALLOW_COPY_AND_ASSIGN(Environment);
 };
 
 
 // Visitor base class to visit each instruction and computation in a flow
 // graph as defined by a reversed list of basic blocks.
 class FlowGraphVisitor : public ValueObject {
  public:
@@ skipping 23 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_