Include AVX512 in listed HardwareIntrinsics

[stephentoub]

.NET 8 includes support for AVX512. HardwareIntrinsics.GetFullInfo should factor that in:
https://github.com/dotnet/BenchmarkDotNet/blob/master/src/BenchmarkDotNet/Portability/Cpu/HardwareIntrinsics.cs#L45-L91

[adamsitnik]

It should be very easy to implement, we just need someone with the AVX512 hardware to be able to test it.

[nietras]

Related to this I have been observing some weird issues related to benchmarking on AVX512, see https://mastodon.social/@nietras/110871324242154513

This claims Vector512 being run on net7.0 runtime, and fails running IndexOfAny. Command is something like:

dotnet run -c Release -f net8.0 --project src\Sep.Benchmarks\Sep.Benchmarks.csproj -- -m --runtimes net70 net80 

all code can be found in net8.0 branch of Sep: nietras/Sep#23

IndexOfAny fails with:

[nietras]

Ah I think I get it some of this, this is due to how I set this up perhaps, I use Params for parametizing the parsers to run, this list is then defined for "-f net8.0" then BDN runs each params for each runtime, but what and how it then uses the params for the Vector512 path on net7.0 runtime I do not know. I always struggle with BDN here since parametizing things at runtime is ... not easy.

I do not know how IndexOfAny then fails either but presumably this refers to "net8.0 version" of that code on net7.0 runtime then...