Add missing initializations of p_perminfo
In
a61b1f74823, we failed to update transformFromClauseItem() and
buildNSItemFromLists() to set ParseNamespaceItem.p_perminfo causing
it to point to garbage.
Pointed out by Tom Lane.
Reported-by: Farias de Oliveira <matheusfarias519@gmail.com>
Discussion: https://postgr.es/m/
3173476.
1689286373%40sss.pgh.pa.us
Backpatch-through: 16