Let DocIdSetIterator optimize loading into a FixedBitSet.

[jpountz]

This is an iteration on #14064. The benefits of this approach are that the API is a bit nicer and allows optimizing not only when doc IDs are stored in an int[]. The downside is that it only helps non-scoring disjunctions for now, but we can look into scoring disjunctions later on.

[jpountz]

luceneutil still gives a big speedup on wikibigall:

                            TaskQPS baseline      StdDevQPS my_modified_version      StdDev                Pct diff p-value
                      DismaxTerm      615.71      (6.0%)      601.37      (5.7%)   -2.3% ( -13% -    9%) 0.528
                    CombinedTerm       32.69      (2.3%)       32.05      (1.6%)   -2.0% (  -5% -    1%) 0.114
             CountFilteredOrMany        3.68      (6.2%)        3.64      (5.0%)   -1.2% ( -11% -   10%) 0.736
                            Term      486.74      (5.4%)      481.06      (3.6%)   -1.2% (  -9% -    8%) 0.688
             CountFilteredPhrase       25.50      (2.0%)       25.23      (1.6%)   -1.1% (  -4% -    2%) 0.365
                     OrStopWords       36.92      (3.0%)       36.60      (4.6%)   -0.9% (  -8% -    6%) 0.720
                      OrHighHigh       57.11      (3.0%)       56.62      (5.0%)   -0.8% (  -8% -    7%) 0.747
          CountFilteredOrHighMed       67.39      (0.9%)       66.92      (1.2%)   -0.7% (  -2% -    1%) 0.285
         CountFilteredOrHighHigh       56.61      (1.1%)       56.24      (1.6%)   -0.7% (  -3% -    2%) 0.459
                      AndHighMed      131.57      (2.5%)      130.73      (2.7%)   -0.6% (  -5% -    4%) 0.695
                  FilteredPhrase       30.22      (0.9%)       30.06      (0.3%)   -0.5% (  -1% -    0%) 0.194
                    FilteredTerm      156.35      (2.1%)      155.49      (3.2%)   -0.5% (  -5% -    4%) 0.751
                          Fuzzy1       83.79      (1.7%)       83.42      (3.0%)   -0.4% (  -4% -    4%) 0.768
                     CountPhrase        4.28      (2.9%)        4.26      (1.2%)   -0.4% (  -4% -    3%) 0.782
                        Or3Terms      181.12      (1.7%)      180.43      (2.9%)   -0.4% (  -4% -    4%) 0.801
                     AndHighHigh       45.52      (3.1%)       45.34      (3.0%)   -0.4% (  -6% -    5%) 0.845
                       And3Terms      180.31      (1.9%)      179.72      (1.7%)   -0.3% (  -3% -    3%) 0.771
                          Fuzzy2       78.96      (1.5%)       78.72      (2.8%)   -0.3% (  -4% -    4%) 0.836
             FilteredAndHighHigh       63.19      (1.9%)       63.05      (1.2%)   -0.2% (  -3% -    2%) 0.820
                        PKLookup      284.36      (1.1%)      283.79      (2.8%)   -0.2% (  -4% -    3%) 0.884
                       OrHighMed      205.60      (3.0%)      205.45      (4.6%)   -0.1% (  -7% -    7%) 0.976
              FilteredAndHighMed      130.63      (2.6%)      130.71      (1.4%)    0.1% (  -3% -    4%) 0.963
                        Wildcard       79.74      (3.7%)       79.85      (2.2%)    0.1% (  -5% -    6%) 0.943
            FilteredAndStopWords       48.16      (1.9%)       48.22      (1.6%)    0.1% (  -3% -    3%) 0.897
                 AndHighOrMedMed       45.82      (1.4%)       45.90      (1.1%)    0.2% (  -2% -    2%) 0.808
              FilteredOrHighHigh       64.29      (2.4%)       64.44      (2.3%)    0.2% (  -4% -    5%) 0.880
                FilteredOr3Terms      167.12      (1.3%)      167.64      (0.8%)    0.3% (  -1% -    2%) 0.637
                AndMedOrHighHigh       58.62      (2.2%)       58.82      (2.3%)    0.3% (  -4% -    4%) 0.812
                   TermTitleSort      158.66      (1.6%)      159.26      (1.0%)    0.4% (  -2% -    3%) 0.652
              Or2Terms2StopWords      171.04      (2.5%)      171.80      (2.9%)    0.4% (  -4% -    5%) 0.795
     FilteredAnd2Terms2StopWords      198.44      (1.3%)      199.35      (0.6%)    0.5% (  -1% -    2%) 0.463
               FilteredOrHighMed      154.95      (1.5%)      155.67      (1.3%)    0.5% (  -2% -    3%) 0.604
                    AndStopWords       32.77      (2.3%)       32.93      (2.4%)    0.5% (  -4% -    5%) 0.748
             And2Terms2StopWords      167.37      (2.1%)      168.18      (1.7%)    0.5% (  -3% -    4%) 0.689
                  FilteredOrMany       17.15      (1.1%)       17.24      (1.7%)    0.5% (  -2% -    3%) 0.571
                CountAndHighHigh       55.25      (3.0%)       55.54      (1.1%)    0.5% (  -3% -    4%) 0.711
              CombinedOrHighHigh       19.45      (0.2%)       19.59      (0.9%)    0.7% (   0% -    1%) 0.095
                 DismaxOrHighMed      174.72      (2.7%)      175.99      (3.4%)    0.7% (  -5% -    6%) 0.704
             FilteredOrStopWords       43.21      (2.9%)       43.54      (2.8%)    0.8% (  -4% -    6%) 0.674
               CombinedOrHighMed       73.76      (0.4%)       74.38      (1.0%)    0.8% (   0% -    2%) 0.070
      FilteredOr2Terms2StopWords      148.83      (1.8%)      150.09      (1.4%)    0.8% (  -2% -    4%) 0.402
                  FilteredIntNRQ      113.50     (13.5%)      114.47     (14.5%)    0.9% ( -23% -   33%) 0.922
                          IntNRQ      114.55     (13.6%)      115.58     (14.5%)    0.9% ( -23% -   33%) 0.919
              CombinedAndHighMed       55.84      (1.7%)       56.34      (2.0%)    0.9% (  -2% -    4%) 0.445
             CombinedAndHighHigh       15.36      (1.6%)       15.51      (2.0%)    1.0% (  -2% -    4%) 0.402
               FilteredAnd3Terms      193.72      (2.0%)      195.75      (0.9%)    1.0% (  -1% -    4%) 0.283
                 CountAndHighMed      159.57      (3.9%)      161.37      (2.0%)    1.1% (  -4% -    7%) 0.562
                   TermMonthSort     3912.20      (2.7%)     3964.82      (2.4%)    1.3% (  -3% -    6%) 0.405
                       CountTerm    10986.48      (3.0%)    11153.37      (2.4%)    1.5% (  -3% -    7%) 0.373
                DismaxOrHighHigh      119.28      (4.0%)      121.39      (3.8%)    1.8% (  -5% -    9%) 0.475
                      OrHighRare      263.69      (9.0%)      269.30      (9.7%)    2.1% ( -15% -   22%) 0.718
                          OrMany       19.84      (2.1%)       20.31      (2.9%)    2.3% (  -2% -    7%) 0.149
               TermDayOfYearSort      650.76      (3.4%)      666.38      (3.1%)    2.4% (  -3% -    9%) 0.239
                 FilteredPrefix3      131.68      (5.7%)      135.96      (2.8%)    3.2% (  -4% -   12%) 0.256
                         Prefix3      139.59      (6.2%)      144.69      (2.8%)    3.7% (  -5% -   13%) 0.230
                          Phrase       14.52      (8.1%)       15.08      (5.4%)    3.8% (  -8% -   18%) 0.380
                      TermDTSort      285.66      (7.7%)      301.26      (8.6%)    5.5% ( -10% -   23%) 0.289
                  CountOrHighMed      135.38      (2.3%)      189.34      (3.5%)   39.9% (  33% -   46%) 0.000
                 CountOrHighHigh       72.89      (1.6%)      121.23      (5.0%)   66.3% (  58% -   74%) 0.000
                     CountOrMany        6.78     (15.4%)       11.58      (4.8%)   70.7% (  43% -  107%) 0.000