OnceLock: Add note about drop and statics

Author: ianrrees

library/std/src/sync/once_lock.rs

@@ -14,7 +14,10 @@ use crate::sync::Once;
 /// # Examples
 ///
 /// Using `OnceCell` to store a function’s previously computed value (a.k.a.
-/// ‘lazy static’ or ‘memoizing’):
+/// ‘lazy static’ or ‘memoizing’).  Since [`drop`] is not called for static
+/// items at the end of the program (see [the
+/// reference](https://doc.rust-lang.org/reference/destructors.html), objects
+/// stored using this pattern will not have their destructors called.
 ///
 /// ```
 /// use std::collections::HashMap;