... }  ->  true if the value of label X is not one of \"a\", \"b\",
                  \"c\" \thas(label_name)  -> True if that label is present \t! expr
                  -> negation of expr \texpr && expr  -> Short-circuit and \texpr
                  || expr  -> Short-circuit or \t( expr ) -> parens for grouping \tall()
                  or the empty selector -> matches all endpoints. \n Label names are

	if !n.Type().IsPtr() {
		s.Fatalf("expected pointer type: %v", n.Type())
	}
	elem, rtypeExpr := n.Type().Elem(), n.ElemRType
	if count != nil {
		if !elem.IsArray() {
			s.Fatalf("expected array type: %v", elem)
		}
		elem, rtypeExpr = elem.Elem(), n.ElemElemRType
	}
	size := elem.Size()
	// Casting from larger type to smaller one is ok, so for smallest type, do nothing.