fix: keep JS pattern holes and defaults

oxc has no node for a hole in an array pattern or target, so a List
of children dropped them: const [, x] = m lost its hole. A List can
now read its ids from the arena, as bun's indirect lists do, with a
missing node for each hole. A shorthand default in an object
assignment target, which oxc keeps as a field, prints again. The
oracle goes from 9,043 to 9,075 files printed as Prettier prints them.