BUG #15320: = any (array(SQL)) ERROR: invalid memory alloc requestsize 1073741824

The following bug has been logged on the website:

Bug reference:      15320
Logged by:          Zhou Digoal
Email address:      digoal@126.com
PostgreSQL version: 11beta2
Operating system:   CentOS 7.x x64
Description:

the error is:

```
create table tbl (uid int8 primary key, pid int8);
insert into tbl select generate_series(1,100000000), random()*100000;

postgres=# explain select count(*) from tbl where uid = any (array(select
uid from tbl limit 100000000))    ;
                                     QUERY PLAN
        
-------------------------------------------------------------------------------------
 Aggregate  (cost=1635653.23..1635653.24 rows=1 width=8)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=0.00..1635635.23 rows=100000000 width=8)
           ->  Seq Scan on tbl tbl_1  (cost=0.00..2289638.88 rows=139984688
width=8)
   ->  Index Only Scan using pk on tbl  (cost=0.57..17.98 rows=10 width=0)
         Index Cond: (uid = ANY ($0))
(6 rows)

postgres=# explain analyze select count(*) from tbl where uid = any
(array(select uid from tbl limit 100000000))    ;
ERROR:  XX000: invalid memory alloc request size 1073741824
LOCATION:  repalloc, mcxt.c:1050
Time: 24133.852 ms (00:24.134)
```

is it a bug?
thanks, 
best regards. 
digoal