// trivially dominates itself, so we only have to find if it dominates the
// other predecessors. Since the only way out of X is via NormalDest, X can
// only properly dominate a node if NormalDest dominates that node too.
// trivially dominates itself, so we only have to find if it dominates the
// other predecessors. Since the only way out of X is via NormalDest, X can
// only properly dominate a node if NormalDest dominates that node too.