Optimize expressions of the form (expr === true) when expr has boolean type.

vm/flow_graph_optimizer.h

 // 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.
 
 #ifndef VM_FLOW_GRAPH_OPTIMIZER_H_
 #define VM_FLOW_GRAPH_OPTIMIZER_H_
 
 #include "vm/intermediate_language.h"
 
 namespace dart {
 
 template <typename T> class GrowableArray;
 
 class FlowGraphOptimizer : public FlowGraphVisitor {
  public:
   explicit FlowGraphOptimizer(const GrowableArray<BlockEntryInstr*>& blocks)
       : FlowGraphVisitor(blocks) {}
   virtual ~FlowGraphOptimizer() {}
 
   void ApplyICData();
 
+  void OptimizeComputations();
+
   virtual void VisitStaticCall(StaticCallComp* comp, BindInstr* instr);
   virtual void VisitInstanceCall(InstanceCallComp* comp, BindInstr* instr);
   virtual void VisitLoadIndexed(LoadIndexedComp* comp, BindInstr* instr);
   virtual void VisitStoreIndexed(StoreIndexedComp* comp, BindInstr* instr);
   virtual void VisitRelationalOp(RelationalOpComp* comp, BindInstr* instr);
-
   virtual void VisitEqualityCompare(EqualityCompareComp* comp,
                                     BindInstr* instr);
-
   virtual void VisitBind(BindInstr* instr);
 
  private:
   bool TryReplaceWithBinaryOp(BindInstr* instr,
                               InstanceCallComp* comp,
                               Token::Kind op_kind);
   bool TryReplaceWithUnaryOp(BindInstr* instr,
                              InstanceCallComp* comp,
                              Token::Kind op_kind);
 
@@ skipping 54 matching lines @@
 
  private:
   const ParsedFunction& parsed_function_;
   bool still_changing_;
   DISALLOW_COPY_AND_ASSIGN(FlowGraphTypePropagator);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_