Add check for non-smi to the IL and use it for class checks.

runtime/vm/flow_graph_optimizer.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_optimizer.h"
 
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/hash_map.h"
 #include "vm/il_printer.h"
@@ skipping 295 matching lines @@
   return class_id;
 }
 
 
 void FlowGraphOptimizer::AddCheckClass(BindInstr* instr,
                                        InstanceCallComp* comp,
                                        Value* value) {
   // Type propagation has not run yet, we cannot eliminate the check.
   const ICData& unary_checks =
       ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecks());
-  CheckClassComp* check = new CheckClassComp(value, comp, unary_checks);
-  InsertBefore(instr, check, instr->env(), Definition::kEffect);
+  CheckNonSmiComp* check_non_smi = new CheckNonSmiComp(value->Copy(),
+                                                       comp->deopt_id());
+  InsertBefore(instr, check_non_smi, instr->env(), Definition::kEffect);
+  CheckClassComp* check_class = new CheckClassComp(value, comp, unary_checks);
+  InsertBefore(instr, check_class, instr->env(), Definition::kEffect);
 }
 
 
 bool FlowGraphOptimizer::TryReplaceWithArrayOp(BindInstr* instr,
                                                InstanceCallComp* comp,
                                                Token::Kind op_kind) {
   // TODO(fschneider): Optimize []= operator in checked mode as well.
   if (op_kind == Token::kASSIGN_INDEX && FLAG_enable_type_checks) return false;
 
   const intptr_t class_id = ReceiverClassId(comp);
@@ skipping 871 matching lines @@
       DirectChainedHashMap<BindInstr*> child_map(*map);  // Copy map.
       OptimizeRecursive(child, &child_map);
     } else {
       OptimizeRecursive(child, map);  // Reuse map for the last child.
     }
   }
 }
 
 
 }  // namespace dart