Fix expression predicate pushdown not firing before AddExchanges

Before the change, the pushdown of `ConnectorExpression` was fired only
when
- there was some other `TupleDomain` constraint to be pushed down, OR
- during `AddExchanges`, because functional predicate is created there.

This commit enables expression-based pushdown early, allowing further
pushdowns -- like aggregation or join pushdown -- to happen. These need
to happen before `AddExchanges`.

core/trino-main/src/main/java/io/trino/sql/planner/iterative/rule/PushPredicateIntoTableScan.java

@@ -214,7 +214,10 @@ public static Optional<PlanNode> pushFilterIntoTableScan(
         }
 
         // check if new domain is wider than domain already provided by table scan
-        if (constraint.predicate().isEmpty() && newDomain.contains(node.getEnforcedConstraint())) {
+        if (constraint.predicate().isEmpty() &&
+                // TODO do we need to track enforced ConnectorExpression in TableScanNode?
+                TRUE.equals(connectorExpression.orElse(TRUE)) &&
+                newDomain.contains(node.getEnforcedConstraint())) {
             Expression resultingPredicate = createResultingPredicate(
                     plannerContext,
                     session,

plugin/trino-base-jdbc/src/test/java/io/trino/plugin/jdbc/BaseJdbcConnectorTest.java

@@ -222,10 +222,8 @@ public void testAggregationPushdown()
         assertConditionallyPushedDown(
                 getSession(),
                 "SELECT regionkey, sum(nationkey) FROM nation WHERE name LIKE '%N%' GROUP BY regionkey",
-                false, // TODO: hasBehavior(SUPPORTS_PREDICATE_EXPRESSION_PUSHDOWN_WITH_LIKE), --  currently, applyAggregation is not invoked after applyFilter with expression
-                hasBehavior(SUPPORTS_PREDICATE_EXPRESSION_PUSHDOWN_WITH_LIKE)
-                        ? node(AggregationNode.class, node(TableScanNode.class))
-                        : node(FilterNode.class, node(TableScanNode.class)));
+                hasBehavior(SUPPORTS_PREDICATE_EXPRESSION_PUSHDOWN_WITH_LIKE),
+                node(FilterNode.class, node(TableScanNode.class)));
         // aggregation on varchar column
         assertThat(query("SELECT count(name) FROM nation")).isFullyPushedDown();
         // aggregation on varchar column with GROUPING