Templatize AstVisitor with its subclass

src/compiler/ast-loop-assignment-analyzer.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_AST_LOOP_ASSIGNMENT_ANALYZER_H_
 #define V8_COMPILER_AST_LOOP_ASSIGNMENT_ANALYZER_H_
 
 #include "src/ast/ast.h"
 #include "src/bit-vector.h"
 #include "src/zone-containers.h"
@@ skipping 22 matching lines @@
   int GetAssignmentCountForTesting(Scope* scope, Variable* var);
 
  private:
   friend class AstLoopAssignmentAnalyzer;
   explicit LoopAssignmentAnalysis(Zone* zone) : list_(zone) {}
   ZoneVector<std::pair<IterationStatement*, BitVector*>> list_;
 };
 
 
 // The class that performs loop assignment analysis by walking the AST.
-class AstLoopAssignmentAnalyzer : public AstVisitor {
+class AstLoopAssignmentAnalyzer final
+    : public AstVisitor<AstLoopAssignmentAnalyzer> {
  public:
   AstLoopAssignmentAnalyzer(Zone* zone, CompilationInfo* info);
 
   LoopAssignmentAnalysis* Analyze();
 
-#define DECLARE_VISIT(type) void Visit##type(type* node) override;
+#define DECLARE_VISIT(type) void Visit##type(type* node);
   AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT
 
   static int GetVariableIndex(Scope* scope, Variable* var);
 
  private:
   CompilationInfo* info_;
   Zone* zone_;
   ZoneDeque<BitVector*> loop_stack_;
   LoopAssignmentAnalysis* result_;
@@ skipping 10 matching lines @@
   void AnalyzeAssignment(Variable* var);
 
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
   DISALLOW_COPY_AND_ASSIGN(AstLoopAssignmentAnalyzer);
 };
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_AST_LOOP_ASSIGNMENT_ANALYZER_H_