Verify java.util.Arrays against OpenJDK 8u121-b13.

This change just clarifies some change markers.

The change from instanceof to getComponentType() in deepHashCode is
kept because it provides a measurable performance increase, see the
benchmarks in the comment for http://r.android.com/666141.

The change to return early from deepEquals when e2 == null is also
kept. Running the same benchmark with a change to include some null
elements gives the results shown below. That benchmark change is also
included here.

With the current code:

    Trial Report (1 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0001}}
      Results:
        runtime(ns): min=31367.26, 1st qu.=31367.26, median=31367.26, mean=31367.26, 3rd qu.=31367.26, max=31367.26
    Trial Report (2 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0004}}
      Results:
        runtime(ns): min=30724.31, 1st qu.=30724.31, median=30724.31, mean=30724.31, 3rd qu.=30724.31, max=30724.31
    Trial Report (3 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0016}}
      Results:
        runtime(ns): min=30966.47, 1st qu.=30966.47, median=30966.47, mean=30966.47, 3rd qu.=30966.47, max=30966.47
    Trial Report (4 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0256}}
      Results:
        runtime(ns): min=384872.18, 1st qu.=384872.18, median=384872.18, mean=384872.18, 3rd qu.=384872.18, max=384872.18
    Trial Report (5 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=2048}}
      Messages:
        INFO: This experiment does not require a microbenchmark. The granularity of the timer (1.243us) is less than 0.1% of the measured runtime. If all experiments for this benchmark have runtimes greater than 1.243ms, consider the macrobenchmark instrument.
      Results:
        runtime(ns): min=7466868.31, 1st qu.=7466868.31, median=7466868.31, mean=7466868.31, 3rd qu.=7466868.31, max=7466868.31
    Trial Report (6 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0001}}
      Results:
        runtime(ns): min=11564.19, 1st qu.=11564.19, median=11564.19, mean=11564.19, 3rd qu.=11564.19, max=11564.19
    Trial Report (7 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0004}}
      Results:
        runtime(ns): min=11996.46, 1st qu.=11996.46, median=11996.46, mean=11996.46, 3rd qu.=11996.46, max=11996.46
    Trial Report (8 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0016}}
      Results:
        runtime(ns): min=12501.23, 1st qu.=12501.23, median=12501.23, mean=12501.23, 3rd qu.=12501.23, max=12501.23
    Trial Report (9 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0256}}
      Results:
        runtime(ns): min=160199.22, 1st qu.=160199.22, median=160199.22, mean=160199.22, 3rd qu.=160199.22, max=160199.22
    Trial Report (10 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=2048}}
      Messages:
        INFO: This experiment does not require a microbenchmark. The granularity of the timer (1.243us) is less than 0.1% of the measured runtime. If all experiments for this benchmark have runtimes greater than 1.243ms, consider the macrobenchmark instrument.
      Results:
        runtime(ns): min=3677664.68, 1st qu.=3677664.68, median=3677664.68, mean=3677664.68, 3rd qu.=3677664.68, max=3677664.68

Without the e2 == null change:

    Trial Report (1 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0001}}
      Results:
        runtime(ns): min=29784.37, 1st qu.=29784.37, median=29784.37, mean=29784.37, 3rd qu.=29784.37, max=29784.37
    Trial Report (2 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0004}}
      Results:
        runtime(ns): min=29919.63, 1st qu.=29919.63, median=29919.63, mean=29919.63, 3rd qu.=29919.63, max=29919.63
    Trial Report (3 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0016}}
      Results:
        runtime(ns): min=30606.55, 1st qu.=30606.55, median=30606.55, mean=30606.55, 3rd qu.=30606.55, max=30606.55
    Trial Report (4 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=0256}}
      Results:
        runtime(ns): min=390343.22, 1st qu.=390343.22, median=390343.22, mean=390343.22, 3rd qu.=390343.22, max=390343.22
    Trial Report (5 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepEquals, vm=default, parameters={arrayLength=2048}}
      Messages:
        INFO: This experiment does not require a microbenchmark. The granularity of the timer (1.238us) is less than 0.1% of the measured runtime. If all experiments for this benchmark have runtimes greater than 1.238ms, consider the macrobenchmark instrument.
      Results:
        runtime(ns): min=7533281.31, 1st qu.=7533281.31, median=7533281.31, mean=7533281.31, 3rd qu.=7533281.31, max=7533281.31
    Trial Report (6 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0001}}
      Results:
        runtime(ns): min=12169.12, 1st qu.=12169.12, median=12169.12, mean=12169.12, 3rd qu.=12169.12, max=12169.12
    Trial Report (7 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0004}}
      Results:
        runtime(ns): min=12014.69, 1st qu.=12014.69, median=12014.69, mean=12014.69, 3rd qu.=12014.69, max=12014.69
    Trial Report (8 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0016}}
      Results:
        runtime(ns): min=13448.17, 1st qu.=13448.17, median=13448.17, mean=13448.17, 3rd qu.=13448.17, max=13448.17
    Trial Report (9 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=0256}}
      Results:
        runtime(ns): min=164844.00, 1st qu.=164844.00, median=164844.00, mean=164844.00, 3rd qu.=164844.00, max=164844.00
    Trial Report (10 of 10):
      Experiment {instrument=runtime, benchmarkMethod=deepHashCode, vm=default, parameters={arrayLength=2048}}
      Messages:
        INFO: This experiment does not require a microbenchmark. The granularity of the timer (1.238us) is less than 0.1% of the measured runtime. If all experiments for this benchmark have runtimes greater than 1.238ms, consider the macrobenchmark instrument.
      Results:
        runtime(ns): min=3866005.14, 1st qu.=3866005.14, median=3866005.14, mean=3866005.14, 3rd qu.=3866005.14, max=3866005.14

Bug: 35910877
Test: Treehugger
Change-Id: Ic611ce1982073113786e840dd6d80c79a48c384f