Some compilers complain about sub_rteperminfos not being
initialized, evidently because they don't detect that it
is only used and set if isGeneralSelect is true.
Make it follow the long-established pattern for its
sibling variable sub_rtable.
Per reports from Pavel Stehule and the buildfarm.
Discussion: https://postgr.es/m/CAFj8pRDOvGOi-n616kM0Cc7qSbg_nGoS=-haB+D785sUXADqSg@mail.gmail.com
else
{
sub_rtable = NIL; /* not used, but keep compiler quiet */
+ sub_rteperminfos = NIL;
sub_namespace = NIL;
}