[nem-en] usesite

[Vladimir Reshetnikov]

On 2/14/07, Kamil Skalski <kamil.skalski at gmail.com> wrote:
> Use x.GetMemType().CanBeNull
> Check it out in ncc/typing/MType.n

CanBeNull returns false for unconstrained type parameter.
So, it will not help, when we generate GetHashCode for tuples.
I need a kind of
 (x.GetMemType().CanBeNull || x.GetMemType().IsTypeParameter &&
x.GetMemType().HasNotStructConstraint)