I believe the reason we had that check in the first place was because for both `pthread_setname_np` and `pthread_getname_np` man says:
```
CONFORMING TO
These functions are nonstandard GNU extensions; hence the suffix "_np" (nonportable) in the names.
```
However, this `is_gnu` check was never consistently applied; it was
missing in `setName` in the Linux case. It is also missing on all other call sites for other platforms (macOS, iOS, et al.).
Though, that could be because it may only apply to Linux.
I think for a best-effort approach it is okay to drop this. It's probably less non-standard than man makes it out to be.
f10100cf9b