VM: Use BlockIterator in the optimizer consistently for iterating the flow graph

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 8155 matching lines @@
 
   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:
   explicit FlowGraphVisitor(const GrowableArray<BlockEntryInstr*>& block_order)
-      : block_order_(block_order), current_iterator_(NULL) { }
+      : current_iterator_(NULL), block_order_(block_order) { }
   virtual ~FlowGraphVisitor() { }
 
   ForwardInstructionIterator* current_iterator() const {
     return current_iterator_;
   }
 
   // Visit each block in the block order, and for each block its
   // instructions in order from the block entry to exit.
   virtual void VisitBlocks();
 
   // Visit functions for instruction classes, with an empty default
   // implementation.
 #define DECLARE_VISIT_INSTRUCTION(ShortName)                                   \
   virtual void Visit##ShortName(ShortName##Instr* instr) { }
 
   FOR_EACH_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)
 
 #undef DECLARE_VISIT_INSTRUCTION
 
  protected:
-  const GrowableArray<BlockEntryInstr*>& block_order_;
   ForwardInstructionIterator* current_iterator_;
 
  private:
+  const GrowableArray<BlockEntryInstr*>& block_order_;
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 // Helper macros for platform ports.
 #define DEFINE_UNIMPLEMENTED_INSTRUCTION(Name)                                \
   LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {    \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_