Added "emergency collection" to 'io.tmpfile' and 'os.tmpname'

These operations also can give errors for lack of resources, so they
also will try "emergency collections" in case of resource errors.
Because there are now two libraries with that kind of handling,
'resourcetryagain' was moved to the auxiliary library to be shared
by the libraries.

loslib.c

@@ -166,6 +166,8 @@ static int os_tmpname (lua_State *L) {
   char buff[LUA_TMPNAMBUFSIZE];
   int err;
   lua_tmpnam(buff, err);
+  if (err && luaL_resourcetryagain(L))  /* resource failure? */
+    lua_tmpnam(buff, err);  /* try again */
   if (err)
     return luaL_error(L, "unable to generate a unique filename");
   lua_pushstring(L, buff);