Implement STB 34.101.77-2020 `bash` #232

Job	Run time
miri (x86_64-unknown-linux-gnu)	46s
miri (s390x-unknown-linux-gnu)	1m 1s
test-simd	15s
set-msrv / set-msrv	4s
minimal-versions / minimal-versions	40s
build (stable, thumbv7em-none-eabi)	22s
test (1.85.0)	19s
build (1.85.0, thumbv7em-none-eabi)	13s
test (stable)	28s
aarch64-sha3 (1.85.0)	40s
aarch64-sha3 (stable)	36s
build (1.85.0, wasm32-unknown-unknown)	17s
build (stable, wasm32-unknown-unknown)	13s
	5m 54s

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