History of CasFs::readdir 1 change

In crates/flow-casfs/src/main.rs, lines 238–259 on 46fe2c815cc3fe5418562f0a5128d9e685148c29807881f49a587a5a6ea799ba. 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.