Improve return type of array map #21603
| Job | Run time | 
|---|---|
| 3m 11s | |
| 1m 42s | |
| 3m 13s | |
| 3m 8s | |
| 1m 44s | |
| 6m 1s | |
| 1m 52s | |
| 5m 56s | |
| 3m 15s | |
| 2m 7s | |
| 1m 45s | |
| 3m 32s | |
| 1m 42s | |
| 1m 37s | |
| 3m 3s | |
| 2m 52s | |
| 2m 50s | |
| 49m 30s | 
| Job | Run time | 
|---|---|
| 3m 11s | |
| 1m 42s | |
| 3m 13s | |
| 3m 8s | |
| 1m 44s | |
| 6m 1s | |
| 1m 52s | |
| 5m 56s | |
| 3m 15s | |
| 2m 7s | |
| 1m 45s | |
| 3m 32s | |
| 1m 42s | |
| 1m 37s | |
| 3m 3s | |
| 2m 52s | |
| 2m 50s | |
| 49m 30s |