Test upper overflow in `strict_sub_signed`

Co-authored-by: zachs18 <8355914+zachs18@users.noreply.github.com>
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index cf34ab8..7800259 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -830,7 +830,7 @@ pub const fn checked_sub_signed(self, rhs: $SignedT) -> Option<Self> {
         ///
         /// ```should_panic
         /// #![feature(strict_overflow_ops)]
-        #[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub_signed(3);")]
+        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX).strict_sub_signed(-1);")]
         /// ```
         #[unstable(feature = "strict_overflow_ops", issue = "118260")]
         #[must_use = "this returns the result of the operation, \