Add compression benchmarks that capture recent zlib regressions

[ericstj]

Highly compressible data

dotnet/runtime#118457 (comment) includes a comparison and sample benchmark that includes a large number of iterations of highly-compressible data. This regressed in 9.0 and was missed. We should add a benchmark to cover that.

    [Benchmark]
    public void CompressionTest()
    {
        var testData = _testData[TestFile];
        testData.CompressedStream.Position = 0;

        using (var z = new DeflateStream(testData.CompressedStream, CompressionMode.Compress, true))
        {
            for (int i = 0; i < testData.Iterations; i++)
            {
                z.Write(testData.Data);
            }
        }
    }

https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.IO.Compression/TestData/alice29.txt should fit the bill, so simply adding some iterations to

performance/src/benchmarks/micro/libraries/System.IO.Compression/CompressionStreamPerfTestBase.cs

Lines 58 to 64 in b8a4259

	public void Compress()
	{
	CompressedFile.CompressedDataStream.Position = 0; // all benchmarks invocation reuse the same stream, we set Postion to 0 to start at the beginning
	var compressor = CreateStream(CompressedFile.CompressedDataStream, level);
	compressor.Write(CompressedFile.UncompressedData, 0, CompressedFile.UncompressedData.Length);
	}

might be enough to capture.

Heap fragmentation

dotnet/runtime#117949 addresses a case where removal of our custom allocator regressed performance on windows x64.

We were able to reproduce that with a benchmark that @stephentoub wrote:

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System.IO.Compression;

BenchmarkSwitcher.FromAssembly(typeof(Bench).Assembly).Run(args);

public class Bench
{
    private Barrier _barrier = new Barrier(Environment.ProcessorCount - 1);

    [Benchmark]
    public void Test()
    {
        Task.WaitAll(Enumerable
            .Range(0, _barrier.ParticipantCount)
            .Select(_ => Task.Run(() =>
            {
                _barrier.SignalAndWait();
                for (int length = 1; length < 1000; length++)
                {

                    byte[] buffer = new byte[length];
                    Random.Shared.NextBytes(buffer);
                    using (var z = new ZLibStream(new MemoryStream(), CompressionMode.Compress))
                    {
                        for (int i = 0; i < 100; i++)
                        {
                            z.Write(buffer);
                        }
                    }
                }
            })).ToArray());
    }
}

Method	Runtime	Mean	Error	StdDev	Ratio	RatioSD
Test	.NET 8.0	153.2 ms	3.05 ms	8.44 ms	1.00	0.08
Test	.NET 9.0	289.5 ms	5.64 ms	8.61 ms	1.90	0.12