gh-134584: Eliminate redundant refcounting from _CALL_ISINSTANCE
#3768
| Job | Run time |
|---|---|
| 1m 17s | |
| 1s | |
| 1m 18s |
_CALL_ISINSTANCE
#3768
| Job | Run time |
|---|---|
| 1m 17s | |
| 1s | |
| 1m 18s |