[turbofan] Prepare mechanism to enable TF on language subset.

src/ast.h

 // Copyright 2012 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_AST_H_
 #define V8_AST_H_
 
 #include "src/v8.h"
 
 #include "src/assembler.h"
@@ skipping 122 matching lines @@
 
 #define DECLARE_NODE_TYPE(type)                                          \
   void Accept(AstVisitor* v) override;                                   \
   AstNode::NodeType node_type() const final { return AstNode::k##type; } \
   friend class AstNodeFactory;
 
 
 enum AstPropertiesFlag {
   kDontSelfOptimize,
   kDontSoftInline,
+  kDontCrankshaft,
   kDontCache
 };
 
 
 class FeedbackVectorRequirements {
  public:
   FeedbackVectorRequirements(int slots, int ic_slots)
       : slots_(slots), ic_slots_(ic_slots) {}
 
   int slots() const { return slots_; }
@@ skipping 3352 matching lines @@
 
  private:
   Zone* zone_;
   AstValueFactory* ast_value_factory_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_