selftests/pidfd: add PIDFD_INFO_COREDUMP infrastructure

Add PIDFD_INFO_COREDUMP infrastructure so we can use it in tests.

Link: https://lore.kernel.org/[e-mail]
Acked-by: Luca Boccassi <[e-mail]>
Reviewed-by: Alexander Mikhalitsyn <[e-mail]>
Signed-off-by: Christian Brauner <[e-mail]>

tools/testing/selftests/pidfd/pidfd.h

···
 #define PIDFD_INFO_EXIT			(1UL << 3) /* Always returned if available, even if not requested */
 #endif
 
+#ifndef PIDFD_INFO_COREDUMP
+#define PIDFD_INFO_COREDUMP	(1UL << 4)
+#endif
+
+#ifndef PIDFD_COREDUMPED
+#define PIDFD_COREDUMPED	(1U << 0) /* Did crash and... */
+#endif
+
+#ifndef PIDFD_COREDUMP_SKIP
+#define PIDFD_COREDUMP_SKIP	(1U << 1) /* coredumping generation was skipped. */
+#endif
+
+#ifndef PIDFD_COREDUMP_USER
+#define PIDFD_COREDUMP_USER	(1U << 2) /* coredump was done as the user. */
+#endif
+
+#ifndef PIDFD_COREDUMP_ROOT
+#define PIDFD_COREDUMP_ROOT	(1U << 3) /* coredump was done as root. */
+#endif
+
 #ifndef PIDFD_THREAD
 #define PIDFD_THREAD O_EXCL
 #endif
···
 	__u32 fsuid;
 	__u32 fsgid;
 	__s32 exit_code;
+	__u32 coredump_mask;
+	__u32 __spare1;
 };
 
 /*