PS-9753: Investigate Optimizer patches from Enhanced MySQL

https://perconadev.atlassian.net/browse/PS-9753

This commit integrates a patch included in commit 813b18c3 of
https://github.com/enhancedformysql/mysql-8.0.40
related to the optimizer patch.

Upstream commit 9a13c1c refactored the test_quick_select() function,
removing QEP_TAB dependency.
Now, prev_tables and read_tables are passed as arguments.
get_quick_record_count() path passes nullptrs for both.
If the optimizer detected the const table in the query, this information
is not passed to test_quick_select() and may result in nonoptimal range
scan boundaries.

This patch passes const_tables to test_quick_select(), so the behavior
for get_quick_record_count() is the same as before the refactoring
mentioned above.

Author: kamil-holubicki

mysql-test/r/percona_range_optimizer.result

@@ -0,0 +1,13 @@
+CREATE TABLE t1 (a INTEGER, b INTEGER, PRIMARY KEY (a));
+CREATE TABLE t2 (a INTEGER, b INTEGER, PRIMARY KEY (a, b));
+INSERT INTO t1 VALUES (1, 1), (2, 2);
+ANALYZE TABLE t1, t2;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	OK
+test.t2	analyze	status	OK
+EXPLAIN FORMAT=TREE SELECT t1.b FROM t1 JOIN t2 WHERE t1.a = t2.a AND t2.a = 2 AND t2.b >= t1.b AND t2.b <= t1.b+2;
+EXPLAIN
+-> Filter: ((t2.a = 2) and (t2.b >= '2') and (t2.b <= <cache>(('2' + 2))))  (cost=COST rows=3)
+    -> Covering index range scan on t2 using PRIMARY over (a = 2 AND 2 <= b <= 4)  (cost=COST rows=3)
+
+DROP TABLE t1, t2;

mysql-test/t/percona_range_optimizer.test

@@ -0,0 +1,28 @@
+#
+# In the following test, t1 evaluates to const table.
+# Ensure that range optimzer sets the upper scan boundary accordingly.
+# (ensure that b<=4 boundary is set)
+#
+
+CREATE TABLE t1 (a INTEGER, b INTEGER, PRIMARY KEY (a));
+CREATE TABLE t2 (a INTEGER, b INTEGER, PRIMARY KEY (a, b));
+INSERT INTO t1 VALUES (1, 1), (2, 2);
+
+--let $n = 1000
+--disable_query_log
+BEGIN;
+while($n) {
+  --eval INSERT INTO t2 VALUES (2, $n)
+  --dec $n
+}
+COMMIT;
+--enable_query_log
+
+ANALYZE TABLE t1, t2;
+
+--replace_regex /cost=[0-9]*\.[0-9]*/cost=COST/
+EXPLAIN FORMAT=TREE SELECT t1.b FROM t1 JOIN t2 WHERE t1.a = t2.a AND t2.a = 2 AND t2.b >= t1.b AND t2.b <= t1.b+2;
+
+
+# cleanup
+DROP TABLE t1, t2;

sql/sql_optimizer.cc

@@ -6268,9 +6268,13 @@ static ha_rows get_quick_record_count(THD *thd, JOIN_TAB *tab, ha_rows limit,
     keys_to_use.merge(tab->skip_scan_keys);
     MEM_ROOT temp_mem_root(key_memory_test_quick_select_exec,
                            thd->variables.range_alloc_block_size);
+    table_map const_tables = tab->join()->found_const_table_map;
+    table_map read_tables = tab->join()->is_executed()
+                                ? (tab->prefix_tables() & ~tab->added_tables())
+                                : const_tables;
     int error = test_quick_select(
-        thd, thd->mem_root, &temp_mem_root, keys_to_use, 0,
-        0,  // empty table_map
+        thd, thd->mem_root, &temp_mem_root, keys_to_use, const_tables,
+        read_tables,
         limit,
         false,  // don't force quick range
         ORDER_NOT_RELEVANT, tab->table(), tab->skip_records_in_range(),