ofb

cbc+ctr: cut new prereleases #17

Job	Run time
test (1.85.0)	25s
build (1.85.0, wasm32-unknown-unknown)	20s
build (1.85.0, thumbv7em-none-eabi)	20s
test (stable)	16s
minimal-versions / minimal-versions	46s
build (stable, wasm32-unknown-unknown)	18s
build (stable, thumbv7em-none-eabi)	24s
	2m 49s

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