windows compatibility

Author: boazsegev

fio-stl.h

@@ -7657,7 +7657,8 @@ Windows Implementation
 
 static struct {
   int32_t sig;
-  volatile unsigned flag;
+  uint16_t propagate;
+  volatile uint16_t flag;
   void (*callback)(int sig, void *);
   void *udata;
   void (*old)(int sig);