cgen: fix type_default for option type when the default expr is none
#8710
| Job | Run time |
|---|---|
| 44m 4s | |
| 57m 37s | |
| 2h 33m 29s | |
| 2h 18m 58s | |
| 3m 52s | |
| 2h 44m 5s | |
| 9h 22m 5s |
none
#8710
| Job | Run time |
|---|---|
| 44m 4s | |
| 57m 37s | |
| 2h 33m 29s | |
| 2h 18m 58s | |
| 3m 52s | |
| 2h 44m 5s | |
| 9h 22m 5s |