API request: IOperation ancestor extension methods

[jnm2]

Please provide public extension methods Ancestors(), AncestorsAndSelf(), and FirstAncestorOrSelf<T> on IOperation just like the ones publicly provided on SyntaxNode.

I write these helpers in many of my own projects and just recently added them inside an IDE enhancement I contributed.

Here's a usage example from one of the recent times I wrote my own Ancestors extension method:

public static bool IsInsideExpressionTree(IOperation operation)
{
    return operation.Ancestors()
        .Select(ancestor => (ancestor as IAnonymousFunctionOperation)?.Parent as IConversionOperation)
        .FirstOrDefault(functionConversion => functionConversion is not null) is
        {
            Type: { OriginalDefinition: { } anonymousFunctionType },
        }
        && anonymousFunctionType.HasFullName("System", "Linq", "Expressions", nameof(System.Linq.Expressions.Expression));
}

[CyrusNajmabadi]

I strongly think we should do this. We have a put forth a very opinionated tree-api with our syntax models. That tree api comes with lots of niceties in terms of things like navigation/querying. As much as is sensible, the same tree-oriented apis should be available for IOp.