[NativeAOT] System.Numerics.Vectors.Tests fails in Debug build

[filipnavara]

C:\Users\filip_pq4cffv\Documents\runtime\artifacts\bin\coreclr\windows.x64.Debug\ilc-published\ilc "@C:\Users\filip_pq4cffv\Documents\runtime\artifacts\obj\System.Numerics.Vectors.Tests\Debug\net7.0\native\System.Numerics.Vectors.Tests.ilc.rsp"
ILC: C:\Users\filip_pq4cffv\Documents\runtime\src\coreclr\jit\compiler.h:8788
ILC: Assertion failed '!"Unexpected size for SIMD type"' in 'System.Numerics.Vector`1[System.Half]:get_Item(int):System.Half:this' during 'Importation' (IL size 18; hash 0x11284064; MinOpts)

ILC: C:\Users\filip_pq4cffv\Documents\runtime\src\coreclr\jit\compiler.h:8788
ILC: Assertion failed '!"Unexpected size for SIMD type"' in 'System.Numerics.Vector`1[System.Int128]:get_Item(int):System.Int128:this' during 'Importation' (IL size 18; hash 0x165c7d84; MinOpts)

[ghost]

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Issue Details

---

``` C:\Users\filip_pq4cffv\Documents\runtime\artifacts\bin\coreclr\windows.x64.Debug\ilc-published\ilc "@C:\Users\filip_pq4cffv\Documents\runtime\artifacts\obj\System.Numerics.Vectors.Tests\Debug\net7.0\native\System.Numerics.Vectors.Tests.ilc.rsp" ILC: C:\Users\filip_pq4cffv\Documents\runtime\src\coreclr\jit\compiler.h:8788 ILC: Assertion failed '!"Unexpected size for SIMD type"' in 'System.Numerics.Vector`1[System.Half]:get_Item(int):System.Half:this' during 'Importation' (IL size 18; hash 0x11284064; MinOpts) ILC: C:\Users\filip_pq4cffv\Documents\runtime\src\coreclr\jit\compiler.h:8788 ILC: Assertion failed '!"Unexpected size for SIMD type"' in 'System.Numerics.Vector`1[System.Int128]:get_Item(int):System.Int128:this' during 'Importation' (IL size 18; hash 0x165c7d84; MinOpts) ```

Author:	filipnavara
Assignees:	-
Labels:	`area-CodeGen-coreclr`
Milestone:	-

[filipnavara]

There are more targeted repro steps but I hit this with .\build.cmd clr+clr.aot+libs+libs.tests -test /p:TestNativeAot=true on Windows x64 machine.

[jkotas]

Repro steps without NativeAOT:

using System;
using System.Numerics;
using System.Reflection;
using System.Runtime.CompilerServices;

var m = typeof(Vector<Int128>).GetMethod("get_Item");
RuntimeHelpers.PrepareMethod(m.MethodHandle);

[EgorBo]

Fixed in https://github.com/dotnet/runtime/pull/78765