Update library/core/src/alloc/layout.rs

Co-authored-by: Celina G. Val <celinval@amazon.com>

library/core/src/alloc/layout.rs

@@ -346,8 +346,8 @@ impl Layout {
  #[unstable(feature = "alloc_layout_extra", issue = "55724")]
  #[inline]
  // the below modulo operation might be too costly to prove
- // #[ensures(|result| result.is_err() || n == 0 || result.as_ref().unwrap().0.size() % n == 0)]
- #[ensures(|result| result.is_err() || n == 0 || result.as_ref().unwrap().0.size() >= self.size())]
+ #[cfg_attr(not(kani), ensures(|result| result.is_err() || n == 0 || result.as_ref().unwrap().0.size() % n == 0))]
+ #[cfg_attr(kani, ensures(|result| result.is_err() || n == 0 || result.as_ref().unwrap().0.size() >= self.size()))]
  // the below multiplication might be too costly to prove at this time
  // #[ensures(|result| result.is_err() || result.as_ref().unwrap().0.size() == n * result.as_ref().unwrap().1)]
  // use the weaker statement below for now