fd_set is defined by `sys/select.h`. On musl, this header is not
transitively included by the other headers.
Failure message:
```
compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp:761:37: error: unknown type name 'fd_set'; did you mean 'fd_t'?
761 | INTERCEPTOR(int, pselect, int nfds, fd_set *readfds, fd_set *writefds,
| ^~~~~~
| fd_t
```