"fixed" objects kept in a separated list (instead of being kept in

'allgc' list with a bit marking them)

llex.c

@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.66 2013/05/14 15:59:04 roberto Exp roberto $
+** $Id: llex.c,v 2.67 2013/06/19 14:27:00 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -15,6 +15,7 @@
 
 #include "lctype.h"
 #include "ldo.h"
+#include "lgc.h"
 #include "llex.h"
 #include "lobject.h"
 #include "lparser.h"
@@ -64,9 +65,11 @@ static void save (LexState *ls, int c) {
 
 void luaX_init (lua_State *L) {
   int i;
+  TString *e = luaS_new(L, LUA_ENV);  /* create env name */
+  luaC_fix(L, obj2gco(e));  /* never collect this name */
   for (i=0; i<NUM_RESERVED; i++) {
     TString *ts = luaS_new(L, luaX_tokens[i]);
-    luaS_fix(ts);  /* reserved words are never collected */
+    luaC_fix(L, obj2gco(ts));  /* reserved words are never collected */
     ts->tsv.extra = cast_byte(i+1);  /* reserved word */
   }
 }
@@ -163,8 +166,7 @@ void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source,
   ls->linenumber = 1;
   ls->lastline = 1;
   ls->source = source;
-  ls->envn = luaS_new(L, LUA_ENV);  /* create env name */
-  luaS_fix(ls->envn);  /* never collect this name */
+  ls->envn = luaS_new(L, LUA_ENV);  /* get env name */
   luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER);  /* initialize buffer */
 }