Revert 13117: "Enable stub generation using Hydrogen/Lithium (again)"

src/x64/codegen-x64.h

Index: src/x64/codegen-x64.h
diff --git a/src/x64/codegen-x64.h b/src/x64/codegen-x64.h
index 3a7646bd1bb7ff68b959509f6a6acacf02fadd9e..d4440952135d93a0bf7d72df2fd7e92ebbe6bc3f 100644
--- a/src/x64/codegen-x64.h
+++ b/src/x64/codegen-x64.h
@@ -44,10 +44,6 @@ enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
 
 class CodeGenerator: public AstVisitor {
  public:
-  CodeGenerator() {
-    InitializeAstVisitor();
-  }
-
   static bool MakeCode(CompilationInfo* info);
 
   // Printing of AST, etc. as requested by flags.
@@ -67,8 +63,6 @@ class CodeGenerator: public AstVisitor {
                               int pos,
                               bool right_here = false);
 
-  DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
-
  private:
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };