Create a separate space for global property cells

src/heap.h

Index: src/heap.h
===================================================================
--- src/heap.h	(revision 2321)
+++ src/heap.h	(working copy)
@@ -261,6 +261,8 @@
   static OldSpace* old_data_space() { return old_data_space_; }
   static OldSpace* code_space() { return code_space_; }
   static MapSpace* map_space() { return map_space_; }
+  static GlobalPropertyCellSpace* global_property_cell_space() {
+    return global_property_cell_space_; }
   static LargeObjectSpace* lo_space() { return lo_space_; }
 
   static bool always_allocate() { return always_allocate_scope_depth_ != 0; }
@@ -837,6 +839,7 @@
   static OldSpace* old_data_space_;
   static OldSpace* code_space_;
   static MapSpace* map_space_;
+  static GlobalPropertyCellSpace* global_property_cell_space_;
   static LargeObjectSpace* lo_space_;
   static HeapState gc_state_;
 
@@ -924,8 +927,11 @@
   // to Heap::AllocateRaw(size_in_bytes, MAP_SPACE), except that (a) it doesn't
   // have to test the allocation space argument and (b) can reduce code size
   // (since both AllocateRaw and AllocateRawMap are inlined).
-  static inline Object* AllocateRawMap(int size_in_bytes);
+  static inline Object* AllocateRawMap();
 
+  // Allocate an uninitialized object in global property cell space.
+  static inline Object* AllocateRawGlobalPropertyCell();
+
   // Initializes a JSObject based on its map.
   static void InitializeJSObjectFromMap(JSObject* obj,
                                         FixedArray* properties,