History of CasFs::readdir 1 change

In crates/flow-casfs/src/main.rs, lines 238–259 on c2430ac3b728f80a32926e6d0540b6ef68dec852f039d2cf4b8afdea7d25e855. 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 238,259:crates/flow-casfs/src/main.rs.