fn snapshot_at_dominator<'a>(
body: &Body<'_>,
snapshots: &'a IndexVec<BasicBlock, Option<Snapshot>>,
bb: BasicBlock,
) -> &'a Snapshot
fn snapshot_at_dominator<'a>(
body: &Body<'_>,
snapshots: &'a IndexVec<BasicBlock, Option<Snapshot>>,
bb: BasicBlock,
) -> &'a Snapshot