Amazon.com Inc. is joining the ranks of one of Wall Street’s oldest and most exclusive stock indexes: The Dow Jones Industrial Average. The e-commerce pioneer will officially take its position among the 30-company Dow before the open of trading Monday, replacing drugstore operator Walgreens Boots Alliance. S&P Dow Jones Indices opened the door to Amazon’s inclusion in the Dow and Walgreens’ exit to rebalance the index in light of a 3-for-1 stock split by another Dow company, Walmart. Seattle-based Amazon will share membership in the Dow with…