Refactor the compiling pipeline.

src/utils.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1100 matching lines @@
   int ToInt() const { return id_; }
 
   static BailoutId None() { return BailoutId(kNoneId); }
   static BailoutId FunctionEntry() { return BailoutId(kFunctionEntryId); }
   static BailoutId Declarations() { return BailoutId(kDeclarationsId); }
   static BailoutId FirstUsable() { return BailoutId(kFirstUsableId); }
   static BailoutId StubEntry() { return BailoutId(kStubEntryId); }
 
   bool IsNone() const { return id_ == kNoneId; }
   bool operator==(const BailoutId& other) const { return id_ == other.id_; }
+  bool operator!=(const BailoutId& other) const { return id_ != other.id_; }
 
  private:
   static const int kNoneId = -1;
 
   // Using 0 could disguise errors.
   static const int kFunctionEntryId = 2;
 
   // This AST id identifies the point after the declarations have been visited.
   // We need it to capture the environment effects of declarations that emit
   // code (function declarations).
   static const int kDeclarationsId = 3;
 
   // Every FunctionState starts with this id.
   static const int kFirstUsableId = 4;
 
   // Every compiled stub starts with this id.
   static const int kStubEntryId = 5;
 
   int id_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_UTILS_H_