Don't double-allocate mutable heap numbers in the json parser. This removes some stupidity when com…

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 8ddcd8b04fc7a8d0cf4171f598cf2ba50ecfc65f..c3344ec98759a28b767e29f5ba440065f210fe21 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2080,7 +2080,7 @@ class JSObject: public JSReceiver {
   inline void FastPropertyAtPut(FieldIndex index, Object* value);
   inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
   inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
-  void WriteToField(int descriptor, Object* value);
+  inline void WriteToField(int descriptor, Object* value);
 
   // Access to in object properties.
   inline int GetInObjectPropertyOffset(int index);