Add a comment about O_APPEND in openfile for Windows
#682
| Job | Run time |
|---|---|
| 5m 29s | |
| 4m 1s | |
| 4m 37s | |
| 9m 0s | |
| 7m 23s | |
| 7m 53s | |
| 5m 43s | |
| 7m 9s | |
| 6m 51s | |
| 15m 46s | |
| 7m 14s | |
| 6m 18s | |
| 2m 7s | |
| 6m 11s | |
| 2m 23s | |
| 14m 36s | |
| 14m 5s | |
| 27m 45s | |
| 27m 51s | |
| 5m 30s | |
| 4m 50s | |
| 4m 52s | |
| 4m 56s | |
| 5m 22s | |
| 5m 3s | |
| 6m 9s | |
| 5m 58s | |
| 5m 51s | |
| 8m 38s | |
| 11m 38s | |
| 9m 43s | |
| 4h 20m 52s |