Revert the assertion of no palloc's in critical section.
Revert the assertion of no palloc's in critical section.

Per discussion, it still fires too often to be safe to enable in
production. Keep it in master, so that we find the issues, but disable it
in the stable branch.

lisakowen/gpdb,lisakowen/gpdb,ashwinstar/gpdb,lisakowen/gpdb,adam8157/gpdb,50wu/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,lisakowen/gpdb,xinzweb/gpdb,ashwinstar/gpdb,50wu/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,lisakowen/gpdb,jmcatamney/gpdb,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,adam8157/gpdb,lisakowen/gpdb,jmcatamney/gpdb,xinzweb/gpdb,xinzweb/gpdb,ashwinstar/gpdb,lisakowen/gpdb,xinzweb/gpdb,adam8157/gpdb,ashwinstar/gpdb,xinzweb/gpdb,xinzweb/gpdb,jmcatamney/gpdb,lisakowen/gpdb,50wu/gpdb,greenplum-db/gpdb,xinzweb/gpdb,adam8157/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,50wu/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,50wu/gpdb,adam8157/gpdb,50wu/gpdb,adam8157/gpdb,jmcatamney/gpdb,adam8157/gpdb,greenplum-db/gpdb,50wu/gpdb,adam8157/gpdb