[opt](optimizer) Remove unused code to unify code (#38918)

## Proposed changes
Now, Agg's child predicates will  not spread to agg.
    For example:
    select a, sum(b)
    from (
     select a,b from t where a = 1 and b = 2
    ) t
    group by a
    `a = 1` in scan can be propagated to `a` of agg.
    But `b = 2` in scan can not be propagated to `sum(b)` of agg.

Issue Number: #38905
<!--Describe your changes.-->

Co-authored-by: liutang123 <liulijia@gmail.com>

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/PullUpPredicates.java

@@ -35,11 +35,9 @@ import org.apache.doris.nereids.util.ExpressionUtils;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSet.Builder;
 import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 
 import java.util.IdentityHashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -107,21 +105,7 @@ public class PullUpPredicates extends PlanVisitor<ImmutableSet<Expression>, Void
         return cacheOrElse(aggregate, () -> {
             ImmutableSet<Expression> childPredicates = aggregate.child().accept(this, context);
             // TODO
-            List<NamedExpression> outputExpressions = aggregate.getOutputExpressions();
-
-            Map<Expression, Slot> expressionSlotMap
-                    = Maps.newLinkedHashMapWithExpectedSize(outputExpressions.size());
-            for (NamedExpression output : outputExpressions) {
-                if (hasAgg(output)) {
-                    expressionSlotMap.putIfAbsent(
-                            output instanceof Alias ? output.child(0) : output, output.toSlot()
-                    );
-                }
-            }
-            Expression expression = ExpressionUtils.replace(
-                    ExpressionUtils.and(Lists.newArrayList(childPredicates)),
-                    expressionSlotMap
-            );
+            Expression expression = ExpressionUtils.and(Lists.newArrayList(childPredicates));
             Set<Expression> predicates = Sets.newLinkedHashSet(ExpressionUtils.extractConjunction(expression));
             return getAvailableExpressions(predicates, aggregate);
         });

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/InferPredicatesTest.java

@@ -73,6 +73,12 @@ class InferPredicatesTest extends TestWithFeService implements MemoPatternMatchS
                         + "distributed by hash(k2) buckets 1\n"
                         + "properties('replication_num' = '1');");
 
+        createTables("CREATE TABLE `test`.`test_tt` (\n"
+                + "`key` varchar(*) NOT NULL,\n"
+                + "  `value` varchar(*) NULL\n"
+                + ") ENGINE=OLAP\n"
+                + "DISTRIBUTED BY HASH(`key`) BUCKETS 1\n"
+                + "PROPERTIES ('replication_allocation' = 'tag.location.default: 1');");
         connectContext.setDatabase("test");
         connectContext.getSessionVariable().setDisableNereidsRules("PRUNE_EMPTY_PARTITION");
     }
@@ -645,4 +651,42 @@ class InferPredicatesTest extends TestWithFeService implements MemoPatternMatchS
                          ))
                 );
     }
+
+    @Test
+    void testAggMultiAliasWithSameChild() {
+        String sql = "SELECT t.*\n"
+                + "FROM (\n"
+                + "        SELECT `key`, a , b \n"
+                + "        FROM (\n"
+                + "                SELECT `key`,\n"
+                + "                       any_value(value) AS a,\n"
+                + "                       any_value(CAST(value AS double)) AS b\n"
+                + "                FROM (\n"
+                + "                        SELECT `key`, CAST(value AS double) AS value\n"
+                + "                        FROM test_tt\n"
+                + "                        WHERE `key` = '1'\n"
+                + "                ) agg\n"
+                + "                GROUP BY `key`\n"
+                + "        ) proj\n"
+                + ") t\n"
+                + "LEFT JOIN\n"
+                + "( SELECT id, name FROM student) t2\n"
+                + "ON t.`key`=t2.`name`";
+        PlanChecker.from(connectContext).analyze(sql).rewrite().printlnTree();
+        PlanChecker.from(connectContext)
+                .analyze(sql)
+                .rewrite()
+                .matches(
+                        logicalJoin(
+                                any(),
+                                logicalProject(
+                                        logicalFilter(
+                                                logicalOlapScan()
+                                        ).when(filter -> filter.getConjuncts().size() == 1
+                                                && filter.getPredicate().toSql().contains("name = '1'"))
+                                )
+                        ).when(join -> join.getJoinType() == JoinType.LEFT_OUTER_JOIN)
+                );
+
+    }
 }