BUG #14466: can with recursive query add LOOPth variable?

The following bug has been logged on the website:

Bug reference: 14466
Logged by: Zhou Digoal
Email address: digoal(at)126(dot)com
PostgreSQL version: 9.6.1
Operating system: CentOS 6.x x64
Description:

HI,
i have a query need use with recursive, and i need use the loopth in the
loops.
like

```
with recursive s as (
select 1 as level, array[]::int[]||c1||c2 as path, c1, c2 from a where
c1=3071
union all
select array_length(s.path,1)+1 as level, s.path||a.c1, a.c1, a.c2 from s
join a on (s.c2=a.c1 and a.c1<>s.c1 and s.level=$LOOPTH) where s.level<=?
and a.* is not null
)
;
```

use this variable, can filter the result in worker table.

now , i must write the plpgsql function to do this.

best regards.