[nem-en] Compare two MType

[vc]

> > You need to call GetFreshType() on the method, ignore TyVars and match
> > MType returned against MType.Fun. It will have T.123 replaced with a
> > fresh type variable that will be substitued with string.
> 
> Or, better yet do a (untested):
> 
> match (ty.TypeOfMethod (meth).Fix ()) {
>   | Fun (from, _) =>
>     match (from.Fix ().GetFunctionArguments ()) {
>        | t1 :: _ => ty.TryProvide (t1)
>        | _ => false
>     }
>   | _ => Util.ice ()
> }
> 
> which should also work when the defing class of an extension method is
> generic (as oposed to just the method being generic).

This code don't work. It's code work:
protected override IsExtendType (method : IMethod, tyVar : TyVar) : bool
{
  match (method.GetFreshType())
  {
    | (MType.Fun(from, _), _) => 
      match (from.Fix().GetFunctionArguments())
      {
        | paramMType :: _ => paramMType.TryProvide(tyVar);
        | _ => false
      }
    | _ => false
  }
}

But, in all cese, thanks.