Johannes Altmanninger 38d52b7835 Port perf_convert_ascii
The "#[bench]" attribute is not allowed in stable Rust, so keep it behind
a new feature flag. Run on nightly Rust with

    $ cargo bench --features=bechmark
    test tests::encoding::bench::bench_convert_ascii ... bench:     125,988 ns/iter (+/- 1,128) = 1040 MB/s
2023-12-10 14:35:43 +01:00
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2023-12-10 14:35:43 +01:00