minio/sha256-simd provides additional acceleration for SHA256 using
AVX512, SHA Extensions for x86 and ARM64 for ARM.
It provides a drop-in replacement for crypto/sha256 and if the
extensions are not available it falls back to standard crypto/sha256.
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Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
