dna4_revcomp performance improvement about libdna HOT 1 CLOSED

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Benchmark                     Time             CPU   Iterations
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dnax_revcomp            1100681 ns      1017903 ns          693
dnax_replace            1044861 ns      1005879 ns          670
bwa_bench                 99746 ns        96105 ns         7215
bench/dna4_revcomp       104946 ns       101012 ns         6788
bench/revcomp_switch    8606856 ns      8297132 ns           86
bench/revcomp_table4     690612 ns       665682 ns         1043
bench/twiddle            103307 ns       100992 ns         6961
bench/subtract           104198 ns       101468 ns         6921
bench/twiddle_sse42      121528 ns       116531 ns         5985
bench/shuffle             97570 ns        93735 ns         7452
bench/twiddle_avx2       113210 ns       109839 ns         7005
bench/shuffle_avx2        93442 ns        90816 ns         7742