io.c: include vm_core.h for VM_UNREACHABLE

Thanks to Greg L <greg.mpls@gmail.com> for the report

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65779 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/io.c b/io.c
index dc172efc9c..ec90407c86 100644
--- a/io.c
+++ b/io.c
@@ -10707,6 +10707,7 @@ nogvl_wait_for_single_fd(int fd, short events)
     return poll(&fds, 1, -1);
 }
 #else /* !USE_POLL */
+#  include "vm_core.h"
 #  define IOWAIT_SYSCALL "select"
 static int
 nogvl_wait_for_single_fd(int fd, short events)