Fixed Attributes with null argument fails to parse

[JPaja]

Describe the bug

Custom attribute fails to parse when fixed argument is null

[AttributeUsage(AttributeTargets.All, AllowMultiple = true)]
public class TestCase2Attribute : Attribute
{
    public TestCase2Attribute(Type type)
    {
        Type = type;
    }

    public Type Type { get; set; }

}


[TestCase2(null)]
public void FixedTypeArgumentNull()
{
}

To Reproduce

var fixedMethod =.... //get MethodDefinition of FixedTypeArgumentNull
var customAttribute = fixedMethod.CustomAttributes[0];
var fixedArg = customAttribute.Signature.FixedArguments[0];
var element = fixedArg.Element;

Expected behavior

element to be null

Platform

• OS: [Windows 10]
• AsmResolver Version: [e.g. 4.8-dev]

[Washi1337]

Seems like a detail ECMA-335 forgot to mention. Should be fixed now.