Fixes a couple problems with GC of unoptimized code.

runtime/vm/flow_graph.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/flow_graph.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/intermediate_language.h"
 #include "vm/longjump.h"
@@ skipping 737 matching lines @@
   }
   RenameRecursive(entry, &env, live_phis, variable_liveness);
 }
 
 
 void FlowGraph::AttachEnvironment(Instruction* instr,
                                   GrowableArray<Definition*>* env) {
   Environment* deopt_env =
       Environment::From(*env,
                         num_non_copied_params_,
-                        parsed_function_.function());
+                        Code::Handle(parsed_function_.code()));
   instr->SetEnvironment(deopt_env);
   for (Environment::DeepIterator it(deopt_env); !it.Done(); it.Advance()) {
     Value* use = it.CurrentValue();
     use->definition()->AddEnvUse(use);
   }
   if (instr->CanDeoptimize()) {
     instr->env()->set_deopt_id(instr->deopt_id());
   }
 }
 
@@ skipping 429 matching lines @@
 }
 
 
 bool BlockEffects::IsSideEffectFreePath(BlockEntryInstr* from,
                                         BlockEntryInstr* to) const {
   return available_at_[to->postorder_number()]->Contains(
       from->postorder_number());
 }
 
 }  // namespace dart