History of supersedes 2 changes

In crates/hub/src/flow.rs, lines 596–598 on api-unknown-fields. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 596,598:crates/hub/src/flow.rs.