Don't use [operator==] to refer to [==] in DartDoc. It doesn't work.

sdk/lib/collection/linked_hash_set.dart

Index: sdk/lib/collection/linked_hash_set.dart
diff --git a/sdk/lib/collection/linked_hash_set.dart b/sdk/lib/collection/linked_hash_set.dart
index 5addba5b092da40423585967a4167465f153e900..d07c7e929d3ea0d2f116d54cd72d5ac14cbe29ec 100644
--- a/sdk/lib/collection/linked_hash_set.dart
+++ b/sdk/lib/collection/linked_hash_set.dart
@@ -10,7 +10,7 @@ part of dart.collection;
  * The `LinkedHashSet` also keep track of the order that elements were inserted
  * in, and iteration happens in first-to-last insertion order.
  *
- * The elements of a `LinkedHashSet` must have consistent [Object.operator==]
+ * The elements of a `LinkedHashSet` must have consistent [Object.==]
  * and [Object.hashCode] implementations. This means that the `==` operator
  * must define a stable equivalence relation on the elements (reflexive,
  * symmetric, transitive, and consistent over time), and that `hashCode`
@@ -43,7 +43,7 @@ abstract class LinkedHashSet<E> implements HashSet<E> {
    * to not be in the set when asking `contains`.
    *
    * If [equals] or [hashCode] are omitted, the set uses
-   * the elements' intrinsic [Object.operator==] and [Object.hashCode],
+   * the elements' intrinsic [Object.==] and [Object.hashCode],
    * and [isValidKey] is ignored since these operations are assumed
    * to work on all objects.
    *