Allow use of HashSet<T> in HQL IN and Linq Contains()-queries

Queries such as the below fails with "Failed to convert parameter value from a HashSet`1 to a Guid":

The generated SQL contains something like "where xxx.Id in (@p0)" with:
Name0 - Value:System.Collections.Generic.HashSet`1[System.Guid] .

So it fails to recognize the HashSet<T> as a collection that something should be expanded to separate parameters. Not sure if the problem is in the linq provider or in HQL.