allow use of UFCS for delegates

struct X
{
   alias D = int function(X);

   static D F;
}

Then given x, x.F(); which translates in to X.F(x);

Just because F is local to X shouldn't prevent UFCS from working on it. If F was global then we should use it and it would work fine, it's actually safer this way since F is local to X and cannot be hijacked.