By Matt Hardy When Dublin’s Croke Park and Toulouse’s Le Stadium play hosts to this weekend’s Investec Champions Cup semi-finals, it’ll mark a bumper weekend of attendance figures for European rugby’s governing body EPCR. Because the sell-outs across the Irish Sea – for Leinster’s clash with Northampton Saints – and the English Channel – for Toulouse’s tie against Harlequins – will represent the largest cumulative attendance for a semi-final weekend since 2009. In that season 15 years ago, Munster hosted Leinster in Croke Park while Cardiff played Leicester Tigers in Cardiff’s Principality Sta…