chore: Add benchmarks that use dedicated optimization path by System.Linq

[filzrev]

This PR add LINQ benchmarks that described at following URLs.

• https://devblogs.microsoft.com/dotnet/performance-improvements-in-net-8
• https://devblogs.microsoft.com/dotnet/performance-improvements-in-net-9

From benchmark results.
Some dedicated optimization path seems to be used by System.Linq.

Results of Net80OptimizedBenchmark

Method	Mean	Error	StdDev	Gen0	Allocated
SelectToList_SystemLinq	811.08 ns	426.81 ns	23.395 ns	0.9804	4.01 KB
RepeatToList_SystemLinq	58.63 ns	77.59 ns	4.253 ns	0.2658	1.09 KB
RangeSelectToList_SystemLinq	775.82 ns	715.34 ns	39.210 ns	1.0128	4.14 KB
SelectToList_ZLinq	2,997.08 ns	516.19 ns	28.294 ns	0.9804	4.01 KB
RepeatToList_ZLinq	2,452.75 ns	354.05 ns	19.407 ns	0.2632	1.09 KB
RangeSelectToList_ZLinq	2,772.41 ns	295.97 ns	16.223 ns	0.9995	4.09 KB
RangeSelectToList_ZLinqOptimized	2,471.54 ns	180.95 ns	9.918 ns	0.9918	4.05 KB

Results of Net90OptimizedBenchmark

Method	Mean	Error	StdDev	Gen0	Allocated
DistinctFirst_SystemLinq	16.095 ns	14.5952 ns	0.8000 ns	0.0153	64 B
AppendSelectLast_SystemLinq	29.764 ns	24.8648 ns	1.3629 ns	0.0268	112 B
RangeReverseCount_SystemLinq	18.115 ns	6.8303 ns	0.3744 ns	0.0115	48 B
DefaultIfEmptySelectElementAt_SystemLinq	15.344 ns	7.2214 ns	0.3958 ns	0.0115	48 B
ListSkipTakeElementAt_SystemLinq	32.375 ns	18.4966 ns	1.0139 ns	0.0229	96 B
RangeUnionFirst_SystemLinq	32.644 ns	25.5304 ns	1.3994 ns	0.0268	112 B
SelectWhereSelectSum_SystemLinq	3,282.915 ns	47.7935 ns	2.6197 ns	0.0381	168 B
ZDistinctFirst_ZLinq	43.233 ns	8.5557 ns	0.4690 ns	0.0134	56 B
ZAppendSelectLast_ZLinq	2,141.056 ns	282.5460 ns	15.4873 ns	-	-
ZRangeReverseCount_ZLinq	8.600 ns	0.1929 ns	0.0106 ns	-	-
ZDefaultIfEmptySelectElementAt_ZLinq	12.830 ns	12.8783 ns	0.7059 ns	-	-
ZListSkipTakeElementAt_ZLinq	20.908 ns	4.7675 ns	0.2613 ns	-	-
ZRangeUnionFirst_ZLinq	55.177 ns	17.0159 ns	0.9327 ns	0.0229	96 B
ZRangeUnionFirst_ZLinqOptimized	47.520 ns	10.3418 ns	0.5669 ns	0.0134	56 B
ZSelectWhereSelectSum_ZLinq	1,303.368 ns	84.3879 ns	4.6256 ns	-	-

[neuecc]

Thank you.
Hmn... some things might be worse than I imagined.
I'll improve it.

[neuecc]

some ZLinq test is invalid benchmark.
This was causing extreme (far beyond what I had expected) performance degradation.

wrong

        _ = source.Select(i => i * 2)
                  .AsValueEnumerable()
                  .ToList();

right

        _ = source
                  .AsValueEnumerable()
                  .Select(i => i * 2)
                  .ToList();