Corpus for waitid$P_PIDFD:

Coverage	Program
118	openat-mmap-waitid$P_PIDFD
106	getpgrp-pidfd_open-waitid$P_PIDFD
77	getpgrp-pidfd_open-waitid$P_PIDFD
73	perf_event_open-openat$thread_pidfd-dup2-waitid$P_PIDFD
43	waitid$P_PIDFD