Remove unsafe code from System.Linq.MaxMin

[EgorBo]

Note

This PR is AI-generated.

No asm diffs

Also, added [Intrinsic] on top of non-generics Vector classes. The generic ones do have it already.
The intrinsic on a type helps inliner when it runs out of budget, as a hint that these apis (like Vector.Create(Span) or Vector.CopyTo(Span)) are important.

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[Copilot]

Pull request overview

This PR removes explicit Unsafe / MemoryMarshal-based vector loads from System.Linq’s integer min/max implementation, switching to span-based Vector*.Create(ReadOnlySpan<T>) to avoid unsafe code in MaxMin.

Changes:

• Replaced LoadUnsafe + ref/Unsafe.Add iteration with ReadOnlySpan<T> slicing and Vector128/256/512.Create(ReadOnlySpan<T>).
• Kept the same “first vector + interior vectors + last vector” aggregation pattern while removing address comparisons.

[EgorBo]

@MihuBot

[EgorBo]

Note

AI-generated benchmark. Targets only the MaxMin.cs (Min/Max vector path) changes; the new [Intrinsic] attributes on Vector128/256/512 are out of scope.

@EgorBot -arm -amd

using System;
using System.Linq;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

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

public class Bench
{
    private int[] _ints = default!;
    private long[] _longs = default!;
    private byte[] _bytes = default!;

    [Params(32, 256, 4096)]
    public int Length { get; set; }

    [GlobalSetup]
    public void Setup()
    {
        var rng = new Random(42);
        _ints = new int[Length];
        _longs = new long[Length];
        _bytes = new byte[Length];
        for (int i = 0; i < Length; i++)
        {
            _ints[i] = rng.Next();
            _longs[i] = ((long)rng.Next() << 32) | (uint)rng.Next();
            _bytes[i] = (byte)rng.Next(256);
        }
    }

    [Benchmark] public int IntMax() => _ints.Max();
    [Benchmark] public int IntMin() => _ints.Min();
    [Benchmark] public long LongMax() => _longs.Max();
    [Benchmark] public byte ByteMax() => _bytes.Max();
}