Remove HMFs from JIT helpers

[AaronRobinsonMSFT]

Convert JIT_GetFieldAddr and JIT_GetStaticFieldAddr to C#.

• These JIT helpers are only used in EnC scenarios so their
  performance is secondary.

Convert JIT_NewMDArr to C#.

Contributes to #95695

Copilot reviewed 2 out of 15 changed files in this pull request and generated no comments.

Files not reviewed (13)

• src/coreclr/classlibnative/bcltype/arraynative.cpp: Language not supported
• src/coreclr/classlibnative/bcltype/arraynative.h: Language not supported
• src/coreclr/inc/jithelpers.h: Language not supported
• src/coreclr/jit/utils.cpp: Language not supported
• src/coreclr/vm/corelib.h: Language not supported
• src/coreclr/vm/ecalllist.h: Language not supported
• src/coreclr/vm/field.cpp: Language not supported
• src/coreclr/vm/field.h: Language not supported
• src/coreclr/vm/jithelpers.cpp: Language not supported
• src/coreclr/vm/metasig.h: Language not supported
• src/coreclr/vm/qcallentrypoints.cpp: Language not supported
• src/coreclr/vm/reflectioninvocation.cpp: Language not supported
• src/coreclr/vm/runtimehandles.h: Language not supported

Comments suppressed due to low confidence (3)

src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs:1670

• [nitpick] The error message is too generic. Consider providing a more descriptive error message indicating the failure to get the field address.

throw new NullReferenceException();

src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs:1679

• [nitpick] The error message is too generic. Consider providing a more descriptive error message indicating the failure to get the static field address.

throw new NullReferenceException();

src/coreclr/System.Private.CoreLib/src/System/Array.CoreCLR.cs:42

• Ensure that the new method CreateInstanceMDArray is covered by tests.

internal static unsafe object CreateInstanceMDArray(nint typeHandle, uint dwNumArgs, void* pArgList)

[AaronRobinsonMSFT]

@EgorBot -amd -arm

using System;
using System.Runtime.CompilerServices;
using BenchmarkDotNet.Attributes;

public class Bench
{
    [MethodImpl(MethodImplOptions.NoInlining)]
    static object Alloc<T>(int a, int b, int c)
    {
        return new T[a, b, c];
    }

    [Benchmark]
    public object MDInt() => Alloc<int>(1,2,3);

    [Benchmark]
    public object MDObject() => Alloc<object>(1,2,3);

    [Benchmark]
    public object MDGuid() => Alloc<Guid>(1,2,3);
}

[jkotas]

Thank you!