* TSX ends down 176.08 pts, or 1.52 pct, at 11,433.22 * Index has shed more than 7 pct in May * Energy, materials tumble on Spain, China woes * RIM's shares plunge more than 7 pct By Jon Cook TORONTO, May 30 (Reuters) - Toronto's main stock index hit a one-week low on Wednesday as oil and gas and mining firms slumped on increased global growth fears, fueled by the escalating euro zone debt crisis and signs from China that it is not planning a large economic stimulus. R