Rust 1.72 compat

Signed-off-by: Asahi Lina <lina@asahilina.net>

rust/alloc/alloc.rs

@@ -329,6 +329,7 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
     }
 }
 
+#[cfg(not(version("1.72")))]
 #[cfg_attr(not(test), lang = "box_free")]
 #[inline]
 // This signature has to be the same as `Box`, otherwise an ICE will happen.

rust/alloc/boxed.rs

@@ -1217,9 +1217,23 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<#[may_dangle] T: ?Sized, A: Allocator> Drop for Box<T, A> {
+    #[cfg(not(version("1.72")))]
     fn drop(&mut self) {
         // FIXME: Do nothing, drop is currently performed by compiler.
     }
+
+    #[cfg(version("1.72"))]
+    #[inline]
+    fn drop(&mut self) {
+        // the T in the Box is dropped by the compiler before the destructor is run
+
+        let ptr = self.0;
+
+        unsafe {
+            let layout = Layout::for_value_raw(ptr.as_ptr());
+            self.1.deallocate(From::from(ptr.cast()), layout)
+        }
+    }
 }
 
 #[cfg(not(no_global_oom_handling))]