Remove obsolete nbtree equality key comments.
_bt_first reliably uses the same equality key (on each index column) for
initial positioning purposes as the one that _bt_checkkeys can use to
end the scan following commit f09816a0. _bt_first no longer applies its
own independent rules to determine w
Remove obsolete nbtree equality key comments.
_bt_first reliably uses the same equality key (on each index column) for
initial positioning purposes as the one that _bt_checkkeys can use to
end the scan following commit f09816a0. _bt_first no longer applies its
own independent rules to determine w