Option to add extra bits to the ilist_iterator.
Declared in <llvm/ADT/ilist_node_options.h>
template<bool ExtraIteratorBits>
struct ilist_iterator_bits;
Some use-cases (debug-info) need to know whether a position is intended to be half-open or fully open, i.e. whether to include any immediately adjacent debug-info in an operation. This option adds two bits to the iterator class to store that information.