Remove Helper Method Frames (HMF) from Reflection

[AaronRobinsonMSFT]

Convert RuntimeMethodHandle.GetDeclaringType() to managed and QCall.
Convert RuntimeTypeHandle.GetElementType() to managed.
Correct nullability in signature and usage.
Convert RuntimeTypeHandle.GetDeclaringType() to managed and QCalls.
Remove GetRuntimeTypeHelper().

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[AaronRobinsonMSFT]

@EgorBot -intel -arm64 -perf

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

BenchmarkRunner.Run<Bench>(args: args);

public class Bench
{
    struct S;

    [Benchmark]
    public Type Nested() => typeof(S).DeclaringType;

    [Benchmark]
    public Type NotNested() => typeof(Bench).DeclaringType;

    [Benchmark]
    public Type RefElementType() => typeof(Bench[]).GetElementType();

    [Benchmark]
    public Type ValueElementType() => typeof(S[]).GetElementType();
}

[AaronRobinsonMSFT]

@EgorBot -x64 -arm64 -profiler

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

public class Bench
{
    struct S;

    [Benchmark]
    public Type Nested() => typeof(S).DeclaringType;

    [Benchmark]
    public Type NotNested() => typeof(Bench).DeclaringType;

    [Benchmark]
    public Type RefElementType() => typeof(Bench[]).GetElementType();

    [Benchmark]
    public Type ValueElementType() => typeof(S[]).GetElementType();
}

[EgorBo]

@AaronRobinsonMSFT the bot complained that -profiler flag should be used when there are not more than 3 [Benchmark] attributes. I think I should improve error reporting 🙂

[EgorBo]

@EgorBot -x64 -arm64

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

public class Bench
{
    struct S;

    [Benchmark]
    public Type Nested() => typeof(S).DeclaringType;

    [Benchmark]
    public Type NotNested() => typeof(Bench).DeclaringType;

    [Benchmark]
    public Type RefElementType() => typeof(Bench[]).GetElementType();

    [Benchmark]
    public Type ValueElementType() => typeof(S[]).GetElementType();
}

[AaronRobinsonMSFT]

@EgorBot -x64 -arm64 -profiler

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

public class Bench
{
    struct S;

    [Benchmark]
    public Type RefElementType() => typeof(Bench[]).GetElementType();

    [Benchmark]
    public Type ValueElementType() => typeof(S[]).GetElementType();
}

[jkotas]

Suggested change

	if (pMT->IsArray)
	{
	IntPtr handle = GetHandleForArray(pMT);
	return RuntimeTypeHandle.GetRuntimeTypeFromHandle(handle);
	}
	else
	{

I do not think that this is needed. We got rid of the sharing of methodtable for arrays.

[jkotas]

Suggested change

	extern "C" TADDR QCALLTYPE RuntimeTypeHandle_GetDeclaringTypeHandleForGenericVariable(EnregisteredTypeHandle pTypeHandle)
	extern "C" EnregisteredTypeHandle QCALLTYPE RuntimeTypeHandle_GetDeclaringTypeHandleForGenericVariable(EnregisteredTypeHandle pTypeHandle)

Should this return EnregisteredTypeHandle?

[jkotas]

(same for RuntimeTypeHandle::GetElementTypeHandleFromHandle)

[jkotas]

Suggested change

	FCIMPL1(TADDR, RuntimeTypeHandle::GetElementTypeHandleFromHandle, EnregisteredTypeHandle th)
	FCIMPL1(TADDR, RuntimeTypeHandle::GetElementTypeHandle, EnregisteredTypeHandle th)

Omit FromHandle suffix? RuntimeTypeHandle_GetDeclaringTypeHandle does not have it.