Failed to setting CPU affinity over 32-processor via cli arg

[filzrev]

On current version of BenchmarkDotNet implementation.
--affinity command line argument is parsed as int (signed).

So it can't accept value that over int.MaxValue value and it can't specify over 32-processor affinity.

BenchmarkDotNet/src/BenchmarkDotNet/ConsoleArguments/CommandLineOptions.cs

Line 67 in b515068

public int? Affinity { get; set; }

I thought, it need to change affinity parameter to nuint (unsigned) to pass affinity as bit mask.

Note: Currently BenchmarkDotNet seems not support CPU groups. So affinity can set up to 64 logical CPU cores.

BenchmarkDotNet/src/BenchmarkDotNet/Extensions/ProcessExtensions.cs

Lines 45 to 46 in b515068

	// Max supported affinity without CPU groups is 64
	long cpuMask = Environment.ProcessorCount >= 64 ? unchecked((long)0xFFFF_FFFF_FFFF_FFFF) : (1L << Environment.ProcessorCount) - 1;