Optimize away compare256 for short matches #1188

Job	Run time
Build and test (stable, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 15s
Build and test (msrv, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 4s
Clippy	20s
cargo-c dynamic library	15s
QEMU build & test (stable, ubuntu-latest, s390x-unknown-linux-gnu, s390x-linux-gnu-gcc)	49s
Clippy (--no-default-features --features="c-allocator")	20s
Build and test (beta, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 2s
QEMU build & test (stable, ubuntu-latest, i686-unknown-linux-gnu, i686-linux-gnu-gcc)	41s
Clippy (--no-default-features --features="rust-allocator")	16s
Build and test (stable, macos-latest, x86_64-apple-darwin)	1m 25s
Build and test (stable, macos-14, aarch64-apple-darwin)	1m 1s
Smoke-test fuzzing targets (default)	2m 34s
Smoke-test fuzzing targets (c-allocator)	2m 31s
Smoke-test fuzzing targets (stable, macos-14, aarch64-apple-darwin)	2m 34s
Build and test (stable-x86_64-gnu, windows-2022, x86_64-pc-windows-gnu)	1m 41s
vanilla dynamic library	22s
Smoke-test fuzzing targets (rust-allocator)	2m 34s
Miri	1m 47s
run flate2 test suite	17s
wasm32	44s
	23m 32s

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