Function rustc_mir_build::thir::pattern::check_match::check_arms

fn check_arms<'p, 'tcx>(
    cx: &mut MatchCheckCtxt<'p, 'tcx>, 
    arms: &[(&'p Pat<'tcx>, HirId, bool)], 
    source: MatchSource
) -> Matrix<'p, 'tcx>

Check for unreachable patterns.