Describe the bug
Since update 4.6.0 Stryker gives me a null reference exception. This seems to happen because of the newly added support of filtering implicit constructors. See also

As far as i can gather it does not handle the implicit object creation correctly. For example when the implicit object creation is not inside a variable declaration.

For example DoSomething(new("test")); will be null for creation.FirstAncestorOrSelf<VariableDeclarationSyntax>() since there is no variable declaration. This than gives a null reference exception.

See also 52a9961#diff-81655880c375520982183e68e29cb430c74cc9f6d7efe0669d5af8ce7be81debR49

Logs

Expected behavior
Something like a null check on creation.FirstAncestorOrSelf<VariableDeclarationSyntax>()

Desktop (please complete the following information):

• OS: [e.g. Windows]
• Type of project: core
• Framework Version: .NET 8
• Stryker Version: 4.6.0

Additional context

public class Example
{
    public Example(string value) { }

    public static Example Create() => new("test"); // explicit, should be handled correctly

    public static Example CreateImplicit() => new("test"); // implicit, but still in a return statement, should be handled correctly

    public void DoSomething(Example ex) { }

    public void CallWithImplicit()
    {
        DoSomething(new("test")); // <-- implicit object creation, not in a variable declaration, this is probably failing
    }
}