replace some more charAt cases with bracket access
#6251
| Job | Run time |
|---|---|
| 3m 39s | |
| 1m 56s | |
| 48s | |
| 45s | |
| 44s | |
| 46s | |
| 39s | |
| 44s | |
| 47s | |
| 58s | |
| 1m 57s | |
| 1m 26s | |
| 46s | |
| 42s | |
| 52s | |
| 57s | |
| 1m 44s | |
| 1m 9s | |
| 1m 10s | |
| 51s | |
| 59s | |
| 1m 4s | |
| 2m 2s | |
| 48s | |
| 1m 28s | |
| 1m 52s | |
| 48s | |
| 32m 21s |