Implement deoptimization in the SSA compiler as a parallel move.

runtime/vm/intermediate_language.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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 2449 matching lines @@
  private:
   Location dest_;
   Location src_;
 
   DISALLOW_COPY_AND_ASSIGN(MoveOperands);
 };
 
 
 class ParallelMoveInstr : public Instruction {
  public:
-  explicit ParallelMoveInstr() : moves_(4) {
+  ParallelMoveInstr() : moves_(4) {
   }
 
   DECLARE_INSTRUCTION(ParallelMove)
 
   MoveOperands* AddMove(Location dest, Location src) {
     MoveOperands* move = new MoveOperands(dest, src);
     moves_.Add(move);
     return move;
   }
 
@@ skipping 79 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_