Man page for WCOREDUMP says:
WCOREDUMP(wstatus) returns true if the child produced a core dump.
This macro should be employed only if WIFSIGNALED returned true.
This macro is not specified in POSIX.1-2001 and is not
available on some UNIX implementations (e.g., AIX, SunOS). Therefore,
enclose its use inside #ifdef WCOREDUMP ... #endif.
Let's do exactly this.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>