Dollar Tree DLTR.O slid 2%, while the retail index .SPXRT slipped more than 2%. By Medha Singh Nov 16 (Reuters) - Shares in several U.S. retailers slid on Wednesday after Target Corp TGT.N warned of a gloomy outlook for the crucial holiday quarter with surging inflation hitting sales and as it announced plans to save up to $3 billion in cost cuts to shore up profits. But shares in Target's larger competitor Walmart WMT.N edged up 1.1%, a day after lifting its annual sales and profit forecast as demand for groceries held up despite higher prices.