Fix bug in inlining of []= operators.

runtime/vm/flow_graph_optimizer.cc

 // 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 971 matching lines @@
   intptr_t index_scale = FlowGraphCompiler::ElementSizeFor(array_cid);
   *last = new StoreIndexedInstr(new Value(array),
                                 new Value(index),
                                 new Value(stored_value),
                                 needs_store_barrier,
                                 index_scale,
                                 array_cid,
                                 call->deopt_id());
   flow_graph()->AppendTo(cursor,
                          *last,
-                         NULL,
+                         call->env(),
                          Definition::kEffect);
   return true;
 }
 
 
 bool FlowGraphOptimizer::TryInlineRecognizedMethod(const Function& target,
                                                    Instruction* call,
                                                    intptr_t token_pos,
                                                    const ICData& ic_data,
                                                    TargetEntryInstr** entry,
@@ skipping 6764 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *fields);
   }
 }
 
 
 }  // namespace dart