rktio: add some missing #includes in some configurations

racket/src/racket/src/jitstack.c

@@ -743,7 +743,7 @@ void* scheme_jit_find_code_end(void *p) { return NULL; }
 
 void scheme_thread_start_child(Scheme_Thread *child, Scheme_Object *child_thunk)
 {
-  return scheme_do_thread_start_child(child, child_thunk);
+  scheme_do_thread_start_child(child, child_thunk);
 }
 
 #endif

racket/src/rktio/rktio_flock.c

@@ -15,6 +15,7 @@
 #if defined(RKTIO_USE_FCNTL_AND_FORK_FOR_FILE_LOCKS)
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/wait.h>
 typedef struct pair_t { int car, cdr; } pair_t;
 #endif
 

racket/src/rktio/rktio_poll_set.c

@@ -6,6 +6,9 @@
 # include <fcntl.h>
 # include <errno.h>
 # include <math.h>
+# ifdef USE_ULIMIT
+#  include <ulimit.h>
+# endif
 #endif
 #ifdef HAVE_POLL_SYSCALL
 # include <poll.h>

racket/src/rktio/rktio_process.c

@@ -9,6 +9,9 @@
 # include <sys/wait.h>
 # include <errno.h>
 # include <unistd.h>
+# ifdef USE_ULIMIT
+#  include <ulimit.h>
+# endif
 #endif
 
 #if defined(RKTIO_SYSTEM_UNIX) && defined(RKTIO_USE_PTHREADS)