WIFEXITED() cygwin regression

WIFEXITED() cygwin regression

t/run/exit.t:58:    eval { POSIX::WIFEXITED() };
fails on the new cygwin-1.7 with
     5 [main] perl 3500 fork: child -1 - died waiting for longjmp
before initialization, retry 0, exit code 0xC0000005, errno 11
...
until I kill perl, because you must use an argument for WIFEXITED.
It didn't fail before, so I assume it's a cygwin regression, but it
must be fixed in the perl testsuite,
since an empty argument cries for trouble.
Use 0 or 1 as argument, ${^CHILD_ERROR_NATIVE} preferred.