json.h: suppress -Wzero-as-null-pointer-constant Clang warning
#10022
| Job | Run time |
|---|---|
| 1m 36s | |
| 1m 37s | |
| 1m 38s | |
| 2m 57s | |
| 2m 40s | |
| 3m 43s | |
| 3m 7s | |
| 3m 2s | |
| 2m 59s | |
| 3m 8s | |
| 26m 27s |