Don't truncate away non-key attributes for leftmost downlinks.
Don't truncate away non-key attributes for leftmost downlinks.

nbtsort.c does not need to truncate away non-key attributes for the
minimum key of the leftmost page on a level, since this is only used to
build a minus infinity downlink for the level's leftmost page.
Truncating away non-key attributes in advance of truncating away all
attributes in _bt_sortaddtup() does not affect the correctness of CREATE
INDEX, but it is misleading.

Author: Peter Geoghegan
Discussion: ec241377adb56510d39ca5a688baa1a69951d32e@mail.gmail.com

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