Avoid using lightuserdata in internal wrapper code for the math module.

src/modules/math/wrap_Math.cpp

@@ -500,7 +500,7 @@ extern "C" int luaopen_love_math(lua_State *L)
 	// Execute wrap_Math.lua, sending the math table and ffifuncs pointer as args.
 	luaL_loadbuffer(L, math_lua, sizeof(math_lua), "wrap_Math.lua");
 	lua_pushvalue(L, -2);
-	lua_pushlightuserdata(L, &ffifuncs);
+	luax_pushpointerasstring(L, &ffifuncs);
 	lua_call(L, 2, 0);
 
 	return n;