chore: Use more while loop

[He-Pin]

Motivation:
Use more while loops and avoid some allocation.

master:

125] Benchmark                                                                  (path)  Mode  Cnt    Score   Error  Units
125] RegressionBenchmark.main             bench/resources/bug_suite/assertions.jsonnet  avgt         0.326          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.01.jsonnet  avgt         0.073          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.02.jsonnet  avgt        40.602          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.03.jsonnet  avgt        13.352          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.04.jsonnet  avgt        32.769          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.06.jsonnet  avgt         0.448          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.07.jsonnet  avgt         3.253          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.08.jsonnet  avgt         0.062          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.09.jsonnet  avgt         0.068          ms/op
125] RegressionBenchmark.main         bench/resources/cpp_suite/gen_big_object.jsonnet  avgt         1.012          ms/op
125] RegressionBenchmark.main      bench/resources/cpp_suite/large_string_join.jsonnet  avgt         2.059          ms/op
125] RegressionBenchmark.main  bench/resources/cpp_suite/large_string_template.jsonnet  avgt         2.439          ms/op
125] RegressionBenchmark.main             bench/resources/cpp_suite/realistic1.jsonnet  avgt         3.298          ms/op
125] RegressionBenchmark.main             bench/resources/cpp_suite/realistic2.jsonnet  avgt       125.995          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/base64.jsonnet  avgt         0.843          ms/op
125] RegressionBenchmark.main            bench/resources/go_suite/base64Decode.jsonnet  avgt         0.651          ms/op
125] RegressionBenchmark.main       bench/resources/go_suite/base64DecodeBytes.jsonnet  avgt         9.457          ms/op
125] RegressionBenchmark.main       bench/resources/go_suite/base64_byte_array.jsonnet  avgt         1.515          ms/op
125] RegressionBenchmark.main              bench/resources/go_suite/comparison.jsonnet  avgt        23.599          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/comparison2.jsonnet  avgt        75.864          ms/op
125] RegressionBenchmark.main        bench/resources/go_suite/escapeStringJson.jsonnet  avgt         0.050          ms/op
125] RegressionBenchmark.main                   bench/resources/go_suite/foldl.jsonnet  avgt         9.695          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/lstripChars.jsonnet  avgt         0.650          ms/op
125] RegressionBenchmark.main          bench/resources/go_suite/manifestJsonEx.jsonnet  avgt         0.072          ms/op
125] RegressionBenchmark.main          bench/resources/go_suite/manifestTomlEx.jsonnet  avgt         0.089          ms/op
125] RegressionBenchmark.main         bench/resources/go_suite/manifestYamlDoc.jsonnet  avgt         0.076          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/member.jsonnet  avgt         0.731          ms/op
125] RegressionBenchmark.main                bench/resources/go_suite/parseInt.jsonnet  avgt         0.052          ms/op
125] RegressionBenchmark.main                 bench/resources/go_suite/reverse.jsonnet  avgt        11.621          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/rstripChars.jsonnet  avgt         0.647          ms/op
125] RegressionBenchmark.main              bench/resources/go_suite/stripChars.jsonnet  avgt         0.632          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/substr.jsonnet  avgt         0.173          ms/op
125] RegressionBenchmark.main           bench/resources/sjsonnet_suite/setDiff.jsonnet  avgt         0.493          ms/op
125] RegressionBenchmark.main          bench/resources/sjsonnet_suite/setInter.jsonnet  avgt         0.443          ms/op
125] RegressionBenchmark.main          bench/resources/sjsonnet_suite/setUnion.jsonnet  avgt         0.792          ms/op
125/125, SUCCESS] ./mill bench.runRegressions 438s

current:

125] Benchmark                                                                  (path)  Mode  Cnt   Score   Error  Units
125] RegressionBenchmark.main             bench/resources/bug_suite/assertions.jsonnet  avgt        0.328          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.01.jsonnet  avgt        0.103          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.02.jsonnet  avgt       42.077          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.03.jsonnet  avgt       13.699          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.04.jsonnet  avgt       33.063          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.06.jsonnet  avgt        0.411          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.07.jsonnet  avgt        3.003          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.08.jsonnet  avgt        0.059          ms/op
125] RegressionBenchmark.main               bench/resources/cpp_suite/bench.09.jsonnet  avgt        0.066          ms/op
125] RegressionBenchmark.main         bench/resources/cpp_suite/gen_big_object.jsonnet  avgt        0.973          ms/op
125] RegressionBenchmark.main      bench/resources/cpp_suite/large_string_join.jsonnet  avgt        1.987          ms/op
125] RegressionBenchmark.main  bench/resources/cpp_suite/large_string_template.jsonnet  avgt        2.367          ms/op
125] RegressionBenchmark.main             bench/resources/cpp_suite/realistic1.jsonnet  avgt        3.579          ms/op
125] RegressionBenchmark.main             bench/resources/cpp_suite/realistic2.jsonnet  avgt       88.964          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/base64.jsonnet  avgt        0.839          ms/op
125] RegressionBenchmark.main            bench/resources/go_suite/base64Decode.jsonnet  avgt        0.641          ms/op
125] RegressionBenchmark.main       bench/resources/go_suite/base64DecodeBytes.jsonnet  avgt        9.608          ms/op
125] RegressionBenchmark.main       bench/resources/go_suite/base64_byte_array.jsonnet  avgt        1.477          ms/op
125] RegressionBenchmark.main              bench/resources/go_suite/comparison.jsonnet  avgt       24.221          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/comparison2.jsonnet  avgt       80.209          ms/op
125] RegressionBenchmark.main        bench/resources/go_suite/escapeStringJson.jsonnet  avgt        0.050          ms/op
125] RegressionBenchmark.main                   bench/resources/go_suite/foldl.jsonnet  avgt        9.614          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/lstripChars.jsonnet  avgt        0.628          ms/op
125] RegressionBenchmark.main          bench/resources/go_suite/manifestJsonEx.jsonnet  avgt        0.072          ms/op
125] RegressionBenchmark.main          bench/resources/go_suite/manifestTomlEx.jsonnet  avgt        0.093          ms/op
125] RegressionBenchmark.main         bench/resources/go_suite/manifestYamlDoc.jsonnet  avgt        0.077          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/member.jsonnet  avgt        0.750          ms/op
125] RegressionBenchmark.main                bench/resources/go_suite/parseInt.jsonnet  avgt        0.054          ms/op
125] RegressionBenchmark.main                 bench/resources/go_suite/reverse.jsonnet  avgt       11.649          ms/op
125] RegressionBenchmark.main             bench/resources/go_suite/rstripChars.jsonnet  avgt        0.647          ms/op
125] RegressionBenchmark.main              bench/resources/go_suite/stripChars.jsonnet  avgt        0.643          ms/op
125] RegressionBenchmark.main                  bench/resources/go_suite/substr.jsonnet  avgt        0.170          ms/op
125] RegressionBenchmark.main           bench/resources/sjsonnet_suite/setDiff.jsonnet  avgt        0.494          ms/op
125] RegressionBenchmark.main          bench/resources/sjsonnet_suite/setInter.jsonnet  avgt        0.443          ms/op
125] RegressionBenchmark.main          bench/resources/sjsonnet_suite/setUnion.jsonnet  avgt        0.778          ms/op
125/125, SUCCESS] ./mill bench.runRegressions 438s