Include sys/select.h when checking HAVE_RB_FD_INIT

* configure.in: include sys/select.h for fd_mask on AIX
  [Feature #13637]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59440 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.in

@@ -2156,7 +2156,9 @@ AC_CHECK_TYPES([clockid_t], [], [], [@%:@ifdef HAVE_TIME_H
 @%:@endif])
 
 AC_CACHE_VAL([rb_cv_large_fd_select],
-    [AC_CHECK_TYPE(fd_mask, [rb_cv_large_fd_select=yes], [rb_cv_large_fd_select=no])])
+    [AC_CHECK_TYPE(fd_mask, [rb_cv_large_fd_select=yes], [rb_cv_large_fd_select=no], [@%:@ifdef HAVE_SYS_SELECT_H
+@%:@ include <sys/select.h>
+@%:@endif])])
 AS_IF([test "$rb_cv_large_fd_select" = yes], [
     AC_DEFINE(HAVE_RB_FD_INIT, 1)
 ])