[turbofan] Introduce Oddball::to_number_raw and use it for change lowering.

src/objects.h

 // Copyright 2015 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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/assert-scope.h"
@@ skipping 9415 matching lines @@
   bool has_more() { return index_ < data_.length(); }
  private:
   Vector<const T> data_;
   int index_;
 };
 
 
 // The Oddball describes objects null, undefined, true, and false.
 class Oddball: public HeapObject {
  public:
+  // [to_number_raw]: Cached raw to_number computed at startup.
+  inline double to_number_raw() const;
+  inline void set_to_number_raw(double value);
+
   // [to_string]: Cached to_string computed at startup.
   DECL_ACCESSORS(to_string, String)
 
   // [to_number]: Cached to_number computed at startup.
   DECL_ACCESSORS(to_number, Object)
 
   // [to_number]: Cached to_boolean computed at startup.
   DECL_ACCESSORS(to_boolean, Oddball)
 
   // [typeof]: Cached type_of computed at startup.
   DECL_ACCESSORS(type_of, String)
 
   inline byte kind() const;
   inline void set_kind(byte kind);
 
   // ES6 section 7.1.3 ToNumber for Boolean, Null, Undefined.
   MUST_USE_RESULT static inline Handle<Object> ToNumber(Handle<Oddball> input);
 
   DECLARE_CAST(Oddball)
 
   // Dispatched behavior.
   DECLARE_VERIFIER(Oddball)
 
   // Initialize the fields.
   static void Initialize(Isolate* isolate, Handle<Oddball> oddball,
                          const char* to_string, Handle<Object> to_number,
                          bool to_boolean, const char* type_of, byte kind);
 
   // Layout description.
-  static const int kToStringOffset = HeapObject::kHeaderSize;
+  static const int kToNumberRawOffset = HeapObject::kHeaderSize;
+  static const int kToStringOffset = kToNumberRawOffset + kDoubleSize;
   static const int kToNumberOffset = kToStringOffset + kPointerSize;
   static const int kToBooleanOffset = kToNumberOffset + kPointerSize;
   static const int kTypeOfOffset = kToBooleanOffset + kPointerSize;
   static const int kKindOffset = kTypeOfOffset + kPointerSize;
   static const int kSize = kKindOffset + kPointerSize;
 
   static const byte kFalse = 0;
   static const byte kTrue = 1;
   static const byte kNotBooleanMask = ~1;
   static const byte kTheHole = 2;
   static const byte kNull = 3;
   static const byte kArgumentsMarker = 4;
   static const byte kUndefined = 5;
   static const byte kUninitialized = 6;
   static const byte kOther = 7;
   static const byte kException = 8;
   static const byte kOptimizedOut = 9;
 
   typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
                               kSize> BodyDescriptor;
 
+  STATIC_ASSERT(kToNumberRawOffset == HeapNumber::kValueOffset);
   STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
   STATIC_ASSERT(kNull == Internals::kNullOddballKind);
   STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
 };
 
 
 class Cell: public HeapObject {
@@ skipping 1279 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_