Use mutable heapnumbers to store doubles in fields.

src/ast.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 1314 matching lines @@
     bool emit_store_;
     Handle<Map> receiver_type_;
   };
 
   DECLARE_NODE_TYPE(ObjectLiteral)
 
   Handle<FixedArray> constant_properties() const {
     return constant_properties_;
   }
   ZoneList<Property*>* properties() const { return properties_; }
-
   bool fast_elements() const { return fast_elements_; }
-
-  bool has_function() { return has_function_; }
+  bool may_store_doubles() const { return may_store_doubles_; }
+  bool has_function() const { return has_function_; }
 
   // Mark all computed expressions that are bound to a key that
   // is shadowed by a later occurrence of the same key. For the
   // marked expressions, no store code is emitted.
   void CalculateEmitStore(Zone* zone);
 
   enum Flags {
     kNoFlags = 0,
     kFastElements = 1,
     kHasFunction = 1 << 1
   };
 
   struct Accessors: public ZoneObject {
     Accessors() : getter(NULL), setter(NULL) { }
     Expression* getter;
     Expression* setter;
   };
 
  protected:
   ObjectLiteral(Isolate* isolate,
                 Handle<FixedArray> constant_properties,
                 ZoneList<Property*>* properties,
                 int literal_index,
                 bool is_simple,
                 bool fast_elements,
                 int depth,
+                bool may_store_doubles,
                 bool has_function)
       : MaterializedLiteral(isolate, literal_index, is_simple, depth),
         constant_properties_(constant_properties),
         properties_(properties),
         fast_elements_(fast_elements),
+        may_store_doubles_(may_store_doubles),
         has_function_(has_function) {}
 
  private:
   Handle<FixedArray> constant_properties_;
   ZoneList<Property*>* properties_;
   bool fast_elements_;
+  bool may_store_doubles_;
   bool has_function_;
 };
 
 
 // Node for capturing a regexp literal.
 class RegExpLiteral: public MaterializedLiteral {
  public:
   DECLARE_NODE_TYPE(RegExpLiteral)
 
   Handle<String> pattern() const { return pattern_; }
@@ skipping 1464 matching lines @@
     return NewLiteral(isolate_->factory()->NewNumber(number, TENURED));
   }
 
   ObjectLiteral* NewObjectLiteral(
       Handle<FixedArray> constant_properties,
       ZoneList<ObjectLiteral::Property*>* properties,
       int literal_index,
       bool is_simple,
       bool fast_elements,
       int depth,
+      bool may_store_doubles,
       bool has_function) {
     ObjectLiteral* lit = new(zone_) ObjectLiteral(
         isolate_, constant_properties, properties, literal_index,
-        is_simple, fast_elements, depth, has_function);
+        is_simple, fast_elements, depth, may_store_doubles, has_function);
     VISIT_AND_RETURN(ObjectLiteral, lit)
   }
 
   ObjectLiteral::Property* NewObjectLiteralProperty(bool is_getter,
                                                     FunctionLiteral* value) {
     ObjectLiteral::Property* prop =
         new(zone_) ObjectLiteral::Property(is_getter, value);
     prop->set_key(NewLiteral(value->name()));
     return prop;  // Not an AST node, will not be visited.
   }
@@ skipping 172 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_