LUAL_BUFFERSIZE affects the API, so it is better not to change it

between releases of the same version. (The long double case seems
to be too rare, so that should not be a problem; moreover, that
case is related to a bug)

luaconf.h

@@ -1,5 +1,5 @@
 /*
-** $Id: luaconf.h,v 1.240 2015/01/13 19:50:30 roberto Exp roberto $
+** $Id: luaconf.h,v 1.241 2015/01/16 17:15:52 roberto Exp roberto $
 ** Configuration file for Lua
 ** See Copyright Notice in lua.h
 */
@@ -698,7 +698,8 @@
 #if defined(LUA_REAL_LONGDOUBLE)
 #define LUAL_BUFFERSIZE		8192
 #else
-#define LUAL_BUFFERSIZE		(256 * (int)sizeof(lua_Integer))
+#define LUAL_BUFFERSIZE   ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer)))
+
 #endif
 
 /* }================================================================== */