pub fn cancel_ops(lowered: &mut FlatLowered)Expand description
Cancels out a (StructConstruct, StructDestructure) and (Snap, Desnap) pair.
The algorithm is as follows:
Run backwards analysis with demand to find all the use sites.
When we reach the first item in the pair, check which statement can be removed and
construct the relevant renamed_vars mapping.
See CancelOpsContext::handle_stmt for more detail on when it is safe to remove a statement.