Upvalues collected like everything else (with mark-sweep) instead

of reference count (simpler and better for generational mode)

lfunc.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.h,v 2.14 2014/06/19 18:27:20 roberto Exp roberto $
+** $Id: lfunc.h,v 2.15 2015/01/13 15:49:11 roberto Exp roberto $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -29,21 +29,6 @@
 #define MAXUPVAL	255
 
 
-/*
-** Upvalues for Lua closures
-*/
-struct UpVal {
-  TValue *v;  /* points to stack or to its own value */
-  lu_mem refcount;  /* reference counter */
-  union {
-    struct {  /* (when open) */
-      UpVal *next;  /* linked list */
-      int touched;  /* mark to avoid cycles with dead threads */
-    } open;
-    TValue value;  /* the value (when closed) */
-  } u;
-};
-
 #define upisopen(up)	((up)->v != &(up)->u.value)
 
 
@@ -53,6 +38,7 @@ LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nelems);
 LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
 LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
 LUAI_FUNC void luaF_close (lua_State *L, StkId level);
+LUAI_FUNC void luaF_unlinkupval (UpVal *uv);
 LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
 LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
                                          int pc);