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

The following bug has been logged on the website:

Bug reference: 15320
Logged by: Zhou Digoal
Email address: digoal(at)126(dot)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