handle circular reference in looseEqual (fix #5055)
handle circular reference in looseEqual (fix #5055)

lizhiyao/vue,vuejs/vue,cnchanning/vue,Kingwl/vue,Jinjiang/vue,KingMario/vue,xueyaodeai/vue,Hanks10100/vue,cnchanning/vue,Ddder-FE/vue,Kingwl/vue,vuejs/vue,xueyaodeai/vue,Jinjiang/vue,cnchanning/vue,Kingwl/vue,lizhiyao/vue,vuejs/vue,xueyaodeai/vue,Jinjiang/vue,Kingwl/vue,Ddder-FE/vue,lizhiyao/vue,KingMario/vue,KingMario/vue,optimizely/vue,lizhiyao/vue,xueyaodeai/vue,KingMario/vue,vuejs/vue,Ddder-FE/vue,Ddder-FE/vue,Hanks10100/vue,Hanks10100/vue,Jinjiang/vue,Hanks10100/vue