Add Type::spliceArray(), improve splice_array() array type narrowing
#20937
| Job | Run time |
|---|---|
| 39s | |
| 33s | |
| 23s | |
| 25s | |
| 1m 7s | |
| 26s | |
| 18s | |
| 25s | |
| 15s | |
| 4m 31s |