pgsql: Check that aggregate creator has the right to execute the

Log Message:
-----------
Check that aggregate creator has the right to execute the transition
functions of the aggregate, at both aggregate creation and execution times.

Tags:
----
REL8_0_STABLE

Modified Files:
--------------
    pgsql/src/backend/catalog:
        pg_aggregate.c (r1.69 -> r1.69.4.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_aggregate.c.diff?r1=1.69&r2=1.69.4.1)
    pgsql/src/backend/executor:
        nodeAgg.c (r1.126 -> r1.126.4.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeAgg.c.diff?r1=1.126&r2=1.126.4.1)