Attributes taking object as a parameter have unexpected behavior in AOT

[phil-scott-78]

Description

Given an attribute that take an object as a parameter, when using an Enum it gets converted to an int before being passed to the constructor during AOT

Reproduction Steps

using System.ComponentModel;
using System.Reflection;

var defaultValue = typeof(MyTeam)
    .GetProperty("Quarterback")!
    .GetCustomAttribute<DefaultValueAttribute>()!.Value!;


var customValue = typeof(MyTeam)
    .GetProperty("Backup")!
    .GetCustomAttribute<MyCustomAttribute>()!.Value!;

Console.WriteLine($"{defaultValue.GetType()} {defaultValue}");
Console.WriteLine($"{customValue.GetType()} {customValue}");

internal enum Quarterbacks { Teddy, Lamar, Malik, Stefan }

internal class MyTeam
{
    [DefaultValue(Quarterbacks.Lamar)]
    public Quarterbacks Quarterback { get; set; }
    
    [MyCustom(Quarterbacks.Teddy)]
    public Quarterbacks Backup { get; set; }
}

internal class MyCustomAttribute(object value) : Attribute
{
    public object Value => value;
}

Expected behavior

Quarterbacks Lamar
Quarterbacks Teddy

Actual behavior

System.Int32 1
System.Int32 0

Regression?

Not sure

Known Workarounds

For custom attributes, using a generic attribute will now work. But that doesn't help when wanting to use an existing one like DefaultAttribute

Configuration

• .net 8
• Windows 11
• x64

Not sure

Other information

No response

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[vitek-karas]

I was able to validate (on .NET 8) that on CoreCLR this behaves as expected. On NativeAOT it does reproduce the wrong behavior (converting the values to Int32).
@dotnet/ilc-contrib