Update the definition of borrowing_sub

This ensures that it matches the one in `carrying_add`.

core/src/num/uint_macros.rs

@@ -2445,7 +2445,7 @@ macro_rules! uint_impl {
             //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
             let (a, b) = self.overflowing_sub(rhs);
             let (c, d) = a.overflowing_sub(borrow as $SelfT);
-            (c, b || d)
+            (c, b | d)
         }
 
         /// Calculates `self` - `rhs` with a signed `rhs`