VM: Remove unnecessary field use_kind from IL instructions.

runtime/vm/flow_graph.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_H_
 #define VM_FLOW_GRAPH_H_
 
 #include "vm/growable_array.h"
 #include "vm/intermediate_language.h"
 #include "vm/parser.h"
@@ skipping 115 matching lines @@
     // Always allocate a second index. This index is unused except
     // for Definitions with register pair outputs.
     alloc_ssa_temp_index();
   }
 
   intptr_t InstructionCount() const;
 
   ConstantInstr* GetConstant(const Object& object);
   void AddToInitialDefinitions(Definition* defn);
 
+  enum UseKind { kEffect, kValue };
+
   void InsertBefore(Instruction* next,
                     Instruction* instr,
                     Environment* env,
-                    Definition::UseKind use_kind);
+                    UseKind use_kind);
   void InsertAfter(Instruction* prev,
                    Instruction* instr,
                    Environment* env,
-                   Definition::UseKind use_kind);
+                   UseKind use_kind);
   Instruction* AppendTo(Instruction* prev,
                         Instruction* instr,
                         Environment* env,
-                        Definition::UseKind use_kind);
+                        UseKind use_kind);
 
   // Operations on the flow graph.
   void ComputeSSA(intptr_t next_virtual_register_number,
                   ZoneGrowableArray<Definition*>* inlining_parameters);
 
   // TODO(zerny): Once the SSA is feature complete this should be removed.
   void Bailout(const char* reason) const;
 
 #ifdef DEBUG
   // Verification methods for debugging.
@@ skipping 234 matching lines @@
   // Per block sets of available blocks. Block A is available at the block B if
   // and only if A dominates B and all paths from A to B are free of side
   // effects.
   GrowableArray<BitVector*> available_at_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_H_