MDEV-17239 default max_recursive_iterations 4G -> 1000

A default 4G max_recursive_iterations allows users to far
to easily exhaust CPU, memory and time for a incorrect query.

Reduce this value down to 1000 consistent with Oracle MySQL's
cte_max_recursion_depth.

Author: grooverdan

mysql-test/main/mysqld--help.result

@@ -1605,7 +1605,7 @@ max-join-size 18446744073709551615
 max-length-for-sort-data 1024
 max-password-errors 18446744073709551615
 max-prepared-stmt-count 16382
-max-recursive-iterations 18446744073709551615
+max-recursive-iterations 1000
 max-relay-log-size 1073741824
 max-rowid-filter-size 131072
 max-seeks-for-key 18446744073709551615

mysql-test/main/win_big-mdev-11697.result

@@ -1,3 +1,4 @@
+set max_recursive_iterations=200000;
 create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
 insert into test_table(id, random_data, static_int, static_varchar)
 select id, random_data, 42, 'Hello'
@@ -71,3 +72,4 @@ where variable_name like 'Sort_merge_passes';
 variable_name	case when variable_value > 0 then 'WITH PASSES' else 'NO PASSES' end
 SORT_MERGE_PASSES	WITH PASSES
 drop table test_table;
+set max_recursive_iterations=default;

mysql-test/main/win_big-mdev-11697.test

@@ -1,3 +1,4 @@
+set max_recursive_iterations=200000;
 create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
 
 insert into test_table(id, random_data, static_int, static_varchar)
@@ -48,3 +49,4 @@ from information_schema.session_status
 where variable_name like 'Sort_merge_passes';
 
 drop table test_table;
+set max_recursive_iterations=default;

sql/sys_vars.cc

@@ -2457,7 +2457,7 @@ static Sys_var_ulong Sys_max_recursive_iterations(
        "max_recursive_iterations",
        "Maximum number of iterations when executing recursive queries",
        SESSION_VAR(max_recursive_iterations), CMD_LINE(OPT_ARG),
-       VALID_RANGE(0, UINT_MAX), DEFAULT(UINT_MAX), BLOCK_SIZE(1));
+       VALID_RANGE(0, UINT_MAX), DEFAULT(1000), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_max_sort_length(
        "max_sort_length",