unix: NEED_ALTSTACK must sync with PAGE_SIZE

Co-authored-by: Jonas Böttiger <[email protected]>

Author: workingjubilee

library/std/src/sys/pal/unix/stack_overflow.rs

@@ -142,7 +142,7 @@ mod imp {
             if action.sa_sigaction == SIG_DFL {
                 if !NEED_ALTSTACK.load(Ordering::Relaxed) {
                     // haven't set up our sigaltstack yet
-                    NEED_ALTSTACK.store(true, Ordering::Relaxed);
+                    NEED_ALTSTACK.store(true, Ordering::Release);
                     let handler = unsafe { make_handler(true) };
                     MAIN_ALTSTACK.store(handler.data, Ordering::Relaxed);
                     mem::forget(handler);