Enable c++11 mode for tmxparser

packages/t/tmxparser/xmake.lua

@@ -18,6 +18,7 @@ package("tmxparser")
             add_rules("mode.debug", "mode.release")
             target("tmxparser")
                 set_kind("$(kind)")
+                set_languages("cxx11")
                 add_packages("zlib", "tinyxml2")
                 add_headerfiles("include/**.h")
                 add_includedirs("include", "include/base64")