Update src/alloc/isolated_alloc.rs

Co-authored-by: Ralf Jung <post@ralfj.de>

Author: nia-e

src/alloc/isolated_alloc.rs

@@ -44,10 +44,7 @@ impl IsolatedAlloc {
 
     /// Expands the available memory pool by adding one page.
     fn add_page(&mut self) -> (*mut u8, &mut DenseBitSet<usize>) {
-        // SAFETY: the system page size must always be a power of 2 and nonzero,
-        // and cannot overflow an isize on the host.
-        let page_layout =
-            unsafe { Layout::from_size_align_unchecked(self.page_size, self.page_size) };
+        let page_layout = Layout::from_size_align(self.page_size, self.page_size).unwrap();
         // SAFETY: The system page size, which is the layout size, cannot be 0
         let page_ptr = unsafe { alloc::alloc(page_layout) };
         // `page_infos` has to have one bit for each `COMPRESSION_FACTOR`-sized chunk of bytes in the page.