Normalize accessors.

src/vm/memory.hh

@@ -68,11 +68,11 @@ namespace vm
     }
 
   public:
-    int			heap_size()
+    int			get_heap_size()
     {
       return _heap.size ();      
     }
-    int			stack_size()
+    int			get_stack_size()
     {
       return _stack.size ();
     }