detect registered custom elements (fix #2345)
detect registered custom elements (fix #2345)

th0r/vue,shupan123/vue-fixed-type,diermengdierme/vue,shupan123/vue-fixed-type,th0r/vue,shupan123/vue-fixed-type,th0r/vue,fergaldoyle/vue,diermengdierme/vue,fergaldoyle/vue,diermengdierme/vue,fergaldoyle/vue