moved allot_markers_offset variable into vm struct

vm/vm.hpp

@@ -7,6 +7,7 @@ struct factorvm {
 	/* new objects are allocated here */
 	zone nursery;
 
+
 	// segments
 	inline cell align_page(cell a);
 
@@ -169,6 +170,7 @@ struct factorvm {
 
 	
 	//write barrier
+	cell allot_markers_offset;
 	inline card *addr_to_card(cell a);
 	inline cell card_to_addr(card *c);
 	inline cell card_offset(card *c);

vm/write_barrier.cpp

@@ -5,7 +5,3 @@ using namespace factor;
 cell cards_offset;
 cell decks_offset;
 
-namespace factor
-{
-        cell allot_markers_offset;
-}

vm/write_barrier.hpp

@@ -29,6 +29,5 @@ static const cell deck_bits = (card_bits + 10);
 static const cell deck_size = (1<<deck_bits);
 static const cell addr_deck_mask = (deck_size-1);
 static const cell invalid_allot_marker = 0xff;
-extern cell allot_markers_offset;
 
 }