Rollup merge of #97700 - nzrq:patch-1, r=dtolnay

Add note to documentation of HashSet::intersection

The functionality of the `std::collections::HashSet::intersection(...)` method was slightly surprising to me so I wanted to take a sec to contribute to the documentation for this method.

I've added a `Note:` section if that is appropriate.

library/std/src/collections/hash/set.rs

@@ -588,6 +588,12 @@ where
     /// Visits the values representing the intersection,
     /// i.e., the values that are both in `self` and `other`.
     ///
+    /// When an equal element is present in `self` and `other`
+    /// then the resulting `Intersection` may yield references to
+    /// one or the other. This can be relevant if `T` contains fields which
+    /// are not compared by its `Eq` implementation, and may hold different
+    /// value between the two equal copies of `T` in the two sets.
+    ///
     /// # Examples
     ///
     /// ```