Guid.NewGuid() is 10 times slower on Linux compared to Windows.

The contributor who wants to work on this issue should:

1. Run this simple benchmark from dotnet/performance repository and confirm the problem

git clone https://github.com/dotnet/performance.git
python3 ./performance/scripts/benchmarks_ci.py -f netcoreapp5.0 --filter System.Tests.Perf_Guid.NewGuid

2. Build CoreCLR locally: https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#Build
3. Create a small repro app: https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#repro
4. Use PerfCollect to identify issue https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#PerfCollect
5. Solve the issue