Add DISALLOW_COPY_AND_ASSIGN to subclasses of ValueObject and make ValueObject copyable.

runtime/vm/flow_graph_allocator.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_FLOW_GRAPH_ALLOCATOR_H_
 #define VM_FLOW_GRAPH_ALLOCATOR_H_
 
 #include "vm/growable_array.h"
 #include "vm/intermediate_language.h"
 
@@ skipping 14 matching lines @@
         phis_(10) { }
 
   BitVector* Get(PhiInstr* phi);
 
  private:
   void AddPhi(PhiInstr* phi);
   void Compute();
 
   const FlowGraph& flow_graph_;
   GrowableArray<PhiInstr*> phis_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReachingDefs);
 };
 
 
 class FlowGraphAllocator : public ValueObject {
  public:
   // Number of stack slots needed for a double spill slot.
   static const intptr_t kDoubleSpillSlotFactor = kDoubleSize / kWordSize;
 
   explicit FlowGraphAllocator(const FlowGraph& flow_graph);
 
@@ skipping 612 matching lines @@
 
   AllocationFinger finger_;
 
   DISALLOW_COPY_AND_ASSIGN(LiveRange);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_ALLOCATOR_H_