std result is not as expected on the aarch64 environment.

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

create table bug (i smallint, s1 smallint, s2 smallint, o1 double, o2 double, e1 decimal, e2 decimal);
insert into bug values (1,53,78,53,78,53,78),(2,17,78,17,78,17,78),(3,18,76,18,76,18,76);
insert into bug values (1,53,78,53,78,53,78),(2,17,78,17,78,17,78),(3,18,76,18,76,18,76);
insert into bug values (1,53,78,53,78,53,78),(2,17,78,17,78,17,78),(3,18,76,18,76,18,76);
insert into bug values (1,53,78,53,78,53,78),(2,17,78,17,78,17,78),(3,18,76,18,76,18,76);
select i, count(*), std(s1/s2) from bug22555 group by i order by i;
### 2. What did you expect to see? (Required)
+------+----------+------------+
| i | count(*) | std(s1/s2) |
+------+----------+------------+
| 1 | 4 | 0 |
| 2 | 4 | 0 |
| 3 | 4 | 0 |
+------+----------+------------+
### 3. What did you see instead (Required)
+------+----------+------------------------+
| i | count(*) | std(s1/s2) |
+------+----------+------------------------+
| 1 | 4 | 2.2662332591841973e-17 |
| 2 | 4 | 5.665583147960493e-18 |
| 3 | 4 | 5.665583147960493e-18 |
+------+----------+------------------------+
### 4. What is your TiDB version? (Required)

Release Version: v7.2.0-alpha
Edition: Community
Git Commit Hash: 915108ba7ec8b29c361577c59ba28ba678e33a5a
Git Branch: master
UTC Build Time: 2023-04-21 09:42:01
GoVersion: go1.20.3
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: unistore