added check for conversion 'obj2gco' (and corrections for small

problems detected by this check)

llex.c

@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.77 2014/05/11 14:45:43 roberto Exp roberto $
+** $Id: llex.c,v 2.78 2014/05/21 15:22:02 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -67,10 +67,10 @@ 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 */
+  luaC_fix(L, ts2gco(e));  /* never collect this name */
   for (i=0; i<NUM_RESERVED; i++) {
     TString *ts = luaS_new(L, luaX_tokens[i]);
-    luaC_fix(L, obj2gco(ts));  /* reserved words are never collected */
+    luaC_fix(L, ts2gco(ts));  /* reserved words are never collected */
     ts->tsv.extra = cast_byte(i+1);  /* reserved word */
   }
 }