refactor: simd swar #138

Job	Run time
Test with Miri	1m 45s
msrv	59s
Test stable on ubuntu-latest	1m 28s
Test stable on windows-latest	2m 24s
Test stable on macOS-latest	2m 19s
Test beta on ubuntu-latest	55s
Test beta on windows-latest	1m 35s
Test beta on macOS-latest	1m 39s
Test nightly on ubuntu-latest	47s
Test nightly on windows-latest	2m 49s
Test nightly on macOS-latest	1m 19s
SIMD +sse4.2 on stable	1m 45s
SIMD +sse4.2 on stable	1m 28s
SIMD +avx2 on stable	1m 32s
SIMD +avx2 on stable	1m 28s
SIMD +sse4.2,+avx2 on stable	1m 28s
SIMD +sse4.2,+avx2 on stable	1m 33s
SIMD +sse4.2 on beta	45s
SIMD +sse4.2 on beta	58s
SIMD +avx2 on beta	44s
SIMD +avx2 on beta	46s
SIMD +sse4.2,+avx2 on beta	46s
SIMD +sse4.2,+avx2 on beta	55s
SIMD +sse4.2 on nightly	44s
SIMD +sse4.2 on nightly	56s
SIMD +avx2 on nightly	45s
SIMD +avx2 on nightly	43s
SIMD +sse4.2,+avx2 on nightly	56s
SIMD +sse4.2,+avx2 on nightly	1m 5s
CI is green	1s
	37m 17s

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