perf: Use bit-reversed CRC32 computation with hash/crc32 package

[orisano]

Improved BZIP2 CRC32 calculation by using bit-reversed values with the standard hash/crc32 package. This allows us to leverage hardware CRC32 instructions:

• ARM64: 10-12% speedup using RBIT instruction for bit reversal
• AMD64: ~7% speedup using lookup table for bit reversal

Test data shows consistent improvements on large inputs (>1GB).

Benchmark results (ARM64):
Before:

goos: darwin
goarch: arm64
pkg: github.com/cosnicolaou/pbzip2/internal/bzip2
cpu: Apple M2 Max
BenchmarkDecodeDigits-12    	     330	   3624395 ns/op	  27.59 MB/s	 3612915 B/op	      51 allocs/op
BenchmarkDecodeDigits-12    	     330	   3644010 ns/op	  27.44 MB/s	 3612915 B/op	      51 allocs/op
BenchmarkDecodeDigits-12    	     327	   3732479 ns/op	  26.79 MB/s	 3612947 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      76	  14911637 ns/op	  38.04 MB/s	 3630765 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      78	  14745067 ns/op	  38.47 MB/s	 3630768 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      80	  14724860 ns/op	  38.52 MB/s	 3630758 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	     966	   1359254 ns/op	  12.05 MB/s	 3644075 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	     969	   1265783 ns/op	  12.94 MB/s	 3644089 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	     960	   1255644 ns/op	  13.05 MB/s	 3644082 B/op	      51 allocs/op
BenchmarkWiktionary-12      	       1	205158310917 ns/op	  51.18 MB/s	367216776 B/op	  542483 allocs/op
BenchmarkWiktionary-12      	       1	207003968667 ns/op	  50.72 MB/s	367216776 B/op	  542483 allocs/op
BenchmarkWiktionary-12      	       1	208614686041 ns/op	  50.33 MB/s	367216760 B/op	  542483 allocs/op

After:

goos: darwin
goarch: arm64
pkg: github.com/cosnicolaou/pbzip2/internal/bzip2
cpu: Apple M2 Max
BenchmarkDecodeDigits-12    	     348	   3410393 ns/op	  29.32 MB/s	 3613298 B/op	      51 allocs/op
BenchmarkDecodeDigits-12    	     351	   3401614 ns/op	  29.40 MB/s	 3613299 B/op	      51 allocs/op
BenchmarkDecodeDigits-12    	     351	   3397780 ns/op	  29.43 MB/s	 3613294 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      88	  13143153 ns/op	  43.16 MB/s	 3631144 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      90	  13220578 ns/op	  42.90 MB/s	 3631145 B/op	      51 allocs/op
BenchmarkDecodeNewton-12    	      86	  13253067 ns/op	  42.80 MB/s	 3631149 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	    1011	   1212203 ns/op	  13.52 MB/s	 3644467 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	    1005	   1216967 ns/op	  13.46 MB/s	 3644460 B/op	      51 allocs/op
BenchmarkDecodeRand-12      	     979	   1227642 ns/op	  13.35 MB/s	 3644458 B/op	      51 allocs/op
BenchmarkWiktionary-12      	       1	182874540791 ns/op	  57.41 MB/s	367217160 B/op	  542483 allocs/op
BenchmarkWiktionary-12      	       1	183373722875 ns/op	  57.26 MB/s	367217160 B/op	  542483 allocs/op
BenchmarkWiktionary-12      	       1	182450789709 ns/op	  57.54 MB/s	367217160 B/op	  542483 allocs/op

Benchmark results (AMD64):
Before:

goos: linux
goarch: amd64
pkg: github.com/cosnicolaou/pbzip2/internal/bzip2
cpu: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
BenchmarkDecodeDigits-8   	     225	   5091263 ns/op	  19.64 MB/s	 3612579 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     213	   5065560 ns/op	  19.74 MB/s	 3612580 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     236	   5303314 ns/op	  18.86 MB/s	 3612582 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     225	   5297896 ns/op	  18.88 MB/s	 3612579 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     226	   5209545 ns/op	  19.20 MB/s	 3612580 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     192	   5342964 ns/op	  18.72 MB/s	 3612583 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      57	  19633889 ns/op	  28.89 MB/s	 3630421 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      58	  19672671 ns/op	  28.83 MB/s	 3630428 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      61	  19758570 ns/op	  28.71 MB/s	 3630423 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      61	  19739598 ns/op	  28.73 MB/s	 3630422 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      61	  19763141 ns/op	  28.70 MB/s	 3630418 B/op	      50 allocs/op
BenchmarkDecodeNewton-8   	      62	  19736282 ns/op	  28.74 MB/s	 3630428 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     660	   2487447 ns/op	   6.59 MB/s	 3643743 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     519	   2424910 ns/op	   6.76 MB/s	 3643740 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     681	   2246711 ns/op	   7.29 MB/s	 3643742 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     519	   2818677 ns/op	   5.81 MB/s	 3643742 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     480	   3195923 ns/op	   5.13 MB/s	 3643744 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     426	   2545397 ns/op	   6.44 MB/s	 3643741 B/op	      51 allocs/op
BenchmarkWiktionary-8     	       1	255098611022 ns/op	  41.16 MB/s	367215496 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	250397169327 ns/op	  41.93 MB/s	367215480 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	238734724759 ns/op	  43.98 MB/s	367215464 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	244597109758 ns/op	  42.92 MB/s	367215480 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	252179664415 ns/op	  41.63 MB/s	367215464 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	257409744381 ns/op	  40.79 MB/s	367215480 B/op	  542483 allocs/op

After:

goos: linux
goarch: amd64
pkg: github.com/cosnicolaou/pbzip2/internal/bzip2
cpu: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
BenchmarkDecodeDigits-8   	     238	   5338924 ns/op	  18.73 MB/s	 3612966 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     192	   5548144 ns/op	  18.02 MB/s	 3612965 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     231	   5160329 ns/op	  19.38 MB/s	 3612964 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     234	   5213871 ns/op	  19.18 MB/s	 3612967 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     237	   5183392 ns/op	  19.29 MB/s	 3612964 B/op	      51 allocs/op
BenchmarkDecodeDigits-8   	     234	   5216613 ns/op	  19.17 MB/s	 3612966 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      66	  18813414 ns/op	  30.15 MB/s	 3630812 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      64	  18738811 ns/op	  30.27 MB/s	 3630815 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      64	  18774511 ns/op	  30.21 MB/s	 3630812 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      64	  18803172 ns/op	  30.17 MB/s	 3630817 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      64	  18793181 ns/op	  30.18 MB/s	 3630815 B/op	      51 allocs/op
BenchmarkDecodeNewton-8   	      64	  18779499 ns/op	  30.20 MB/s	 3630812 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     710	   2445520 ns/op	   6.70 MB/s	 3644127 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     573	   2337578 ns/op	   7.01 MB/s	 3644126 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     544	   2681357 ns/op	   6.11 MB/s	 3644127 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     354	   2838394 ns/op	   5.77 MB/s	 3644129 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     439	   2403619 ns/op	   6.82 MB/s	 3644126 B/op	      51 allocs/op
BenchmarkDecodeRand-8     	     687	   2569978 ns/op	   6.38 MB/s	 3644126 B/op	      51 allocs/op
BenchmarkWiktionary-8     	       1	243108260459 ns/op	  43.19 MB/s	367215880 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	233205853611 ns/op	  45.02 MB/s	367215864 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	225249072544 ns/op	  46.61 MB/s	367215864 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	229793144010 ns/op	  45.69 MB/s	367215864 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	233835578682 ns/op	  44.90 MB/s	367215848 B/op	  542483 allocs/op
BenchmarkWiktionary-8     	       1	241809950266 ns/op	  43.42 MB/s	367215864 B/op	  542483 allocs/op

[klauspost]

lgtm. Lint stuff is fixed in #42

[orisano]

I resolved conflicts